[Diagnostics] Use imperative msg for protocol conformance & switch-case fixits

This commit changes fixit messages from a question/suggestion to an
imperative message for protocol conformances and switch-case. Addresses
#67510.

Author: Nishith Shah

include/swift/AST/DiagnosticsSema.def

@@ -2689,9 +2689,9 @@ NOTE(inherited_protocol_does_not_conform,none,
 NOTE(no_witnesses,none,
      "protocol requires "
      "%select{initializer %1|function %1|property %1|subscript}0 with type %2"
-     "%select{|; do you want to add a stub?}3",
+     "%select{|; add a stub for conformance}3",
      (RequirementKind, const ValueDecl *, Type, bool))
-NOTE(missing_witnesses_general,none, "do you want to add protocol stubs?",
+NOTE(missing_witnesses_general,none, "add stubs for conformance",
      ())
 NOTE(ambiguous_witnesses,none,
      "multiple matching "
@@ -2704,7 +2704,7 @@ NOTE(ambiguous_witnesses_wrong_name,none,
      "subscript operators}0 with type %2",
      (RequirementKind, const ValueDecl *, Type))
 NOTE(no_witnesses_type,none,
-     "protocol requires nested type %0; do you want to add it?",
+     "protocol requires nested type %0; add nested type %0 for conformance",
      (const AssociatedTypeDecl *))
 NOTE(default_associated_type_req_fail,none,
      "default type %0 for associated type %1 (from protocol %2) "
@@ -6643,16 +6643,15 @@ WARNING(debug_long_expression, none,
 
 ERROR(empty_switch_stmt,none,
       "'switch' statement body must have at least one 'case' or 'default' "
-      "block; do you want to add a default case?",())
+      "block; add a default case",())
 ERROR(non_exhaustive_switch,none, "switch must be exhaustive", ())
 ERROR(possibly_non_exhaustive_switch,none,
       "the compiler is unable to check that this switch is exhaustive in reasonable time",
       ())
 
 NOTE(missing_several_cases,none,
-     "do you want to add "
-     "%select{missing cases|a default clause}0"
-     "?", (bool))
+     "add "
+     "%select{missing cases|a default clause}0", (bool))
 NOTE(missing_unknown_case,none,
      "handle unknown values using \"@unknown default\"", ())
 

test/AutoDiff/Sema/DerivedConformances/derived_differentiable_diagnostics.swift

@@ -3,7 +3,7 @@
 import _Differentiation
 
 protocol TangentVectorP: Differentiable {
-  // expected-note @+1 {{protocol requires property 'requirement' with type 'Int'; do you want to add a stub?}}
+  // expected-note @+1 {{protocol requires property 'requirement' with type 'Int'; add a stub for conformance}}
   var requirement: Int { get }
 }
 

test/AutoDiff/Sema/differentiable_attr_type_checking.swift

@@ -557,7 +557,7 @@ public protocol DoubleDifferentiableDistribution: DifferentiableDistribution
 
 public protocol HasRequirement {
   @differentiable(reverse)
-  // expected-note @+1 {{protocol requires function 'requirement' with type '<T> (T, T) -> T'; do you want to add a stub?}}
+  // expected-note @+1 {{protocol requires function 'requirement' with type '<T> (T, T) -> T'; add a stub for conformance}}
   func requirement<T: Differentiable>(_ x: T, _ y: T) -> T
 }
 

test/ClangImporter/enum-new.swift

@@ -13,11 +13,11 @@ func test() {
   case .Yellow, .Magenta, .Black, .Cyan: break
   }
 
-  switch getColorOptions() { // expected-error {{switch must be exhaustive}} expected-note{{do you want to add a default clause?}}
+  switch getColorOptions() { // expected-error {{switch must be exhaustive}} expected-note{{add a default clause}}
   case ColorOptions.Pastel: break
   case ColorOptions.Swift: break
   }
 
-  switch 5 as Int16 { // expected-error {{'switch' statement body must have at least one 'case' or 'default' block; do you want to add a default case?}}
+  switch 5 as Int16 { // expected-error {{'switch' statement body must have at least one 'case' or 'default' block; add a default case}}
   }
 }

test/Compatibility/special_func_name.swift

@@ -1,7 +1,7 @@
 // RUN: %target-typecheck-verify-swift -swift-version 4
 
 protocol P1 {
-  static func `init`(_: Int) // expected-note {{protocol requires function 'init' with type '(Int) -> ()'; do you want to add a stub?}}
+  static func `init`(_: Int) // expected-note {{protocol requires function 'init' with type '(Int) -> ()'; add a stub for conformance}}
   // expected-note@-1 {{did you mean 'init'?}}
 }
 
@@ -14,7 +14,7 @@ struct S12 : P1 { // expected-error {{type 'S12' does not conform to protocol 'P
 }
 
 protocol P2 {
-  init(_: Int) // expected-note {{protocol requires initializer 'init(_:)' with type 'Int'; do you want to add a stub?}}
+  init(_: Int) // expected-note {{protocol requires initializer 'init(_:)' with type 'Int'; add a stub for conformance}}
 }
 
 struct S21 : P2 { // expected-error {{type 'S21' does not conform to protocol 'P2'}}

test/Concurrency/async_conformance.swift

@@ -6,15 +6,15 @@ import Foundation
 
 // async objc requirement, sync witness
 @objc protocol Tracker {
-    func track(event: String) async // expected-note {{protocol requires function 'track(event:)' with type '(String) async -> ()'; do you want to add a stub?}}
+    func track(event: String) async // expected-note {{protocol requires function 'track(event:)' with type '(String) async -> ()'; add a stub for conformance}}
 }
 class Dog: NSObject, Tracker { // expected-error {{type 'Dog' does not conform to protocol 'Tracker'}}
     func track(event: String) {} // expected-note {{candidate is not 'async', but @objc protocol requirement is}}
 }
 
 // sync objc requirement, async witness
 @objc protocol Runner {
-    func run(event: String) // expected-note {{protocol requires function 'run(event:)' with type '(String) -> ()'; do you want to add a stub?}}
+    func run(event: String) // expected-note {{protocol requires function 'run(event:)' with type '(String) -> ()'; add a stub for conformance}}
 }
 class Athlete: NSObject, Runner { // expected-error {{type 'Athlete' does not conform to protocol 'Runner'}}
     func run(event: String) async {} // expected-note {{candidate is 'async', but @objc protocol requirement is not}}
@@ -33,7 +33,7 @@ class Foodie: Snacker {
 
 // sync swift protocol, async witness
 protocol Backer {
-    func back(stonk: String) // expected-note {{protocol requires function 'back(stonk:)' with type '(String) -> ()'; do you want to add a stub?}}
+    func back(stonk: String) // expected-note {{protocol requires function 'back(stonk:)' with type '(String) -> ()'; add a stub for conformance}}
 }
 
 class Investor: Backer {  // expected-error {{type 'Investor' does not conform to protocol 'Backer'}}

test/Concurrency/async_initializer.swift

@@ -148,7 +148,7 @@ struct Location {
 }
 
 protocol DefaultConstructable {
-  init() // expected-note {{protocol requires initializer 'init()' with type '()'; do you want to add a stub?}} {{+2:43-43=\n    init() {\n        <#code#>\n    \}\n}}
+  init() // expected-note {{protocol requires initializer 'init()' with type '()'; add a stub for conformance}} {{+2:43-43=\n    init() {\n        <#code#>\n    \}\n}}
 }
 extension Location: DefaultConstructable {} // expected-error {{type 'Location' does not conform to protocol 'DefaultConstructable'}}
 

test/Constraints/associated_types.swift

@@ -62,8 +62,8 @@ protocol XReqt {}
 protocol YReqt {}
 
 protocol SameTypedDefaultWithReqts {
-    associatedtype X: XReqt // expected-note{{protocol requires nested type 'X'; do you want to add it?}}
-    associatedtype Y: YReqt // expected-note{{protocol requires nested type 'Y'; do you want to add it?}}
+    associatedtype X: XReqt // expected-note{{protocol requires nested type 'X'; add nested type 'X' for conformance}}
+    associatedtype Y: YReqt // expected-note{{protocol requires nested type 'Y'; add nested type 'Y' for conformance}}
     static var x: X { get }
     static var y: Y { get }
 }
@@ -86,7 +86,7 @@ struct UsesSameTypedDefaultWithoutSatisfyingReqts: SameTypedDefaultWithReqts {
 }
 
 protocol SameTypedDefaultBaseWithReqts {
-    associatedtype X: XReqt // expected-note{{protocol requires nested type 'X'; do you want to add it?}}
+    associatedtype X: XReqt // expected-note{{protocol requires nested type 'X'; add nested type 'X' for conformance}}
     static var x: X { get }
 }
 protocol SameTypedDefaultDerivedWithReqts: SameTypedDefaultBaseWithReqts {

test/Constraints/issue-52995.swift

@@ -3,7 +3,7 @@
 // https://github.com/apple/swift/issues/52995
 
 protocol Nested {
-    associatedtype U // expected-note {{protocol requires nested type 'U'; do you want to add it?}}
+    associatedtype U // expected-note {{protocol requires nested type 'U'; add nested type 'U' for conformance}}
 }
 
 class A<M> {

test/Constraints/issue-54820.swift

@@ -5,7 +5,7 @@
 protocol Protocol {
   associatedtype Index: Comparable
   subscript(bounds: Range<Index>) -> Int { get }
-  // expected-note@+1 {{protocol requires subscript with type '(Wrapper<Base>.Index) -> Int' (aka '(Base.Index) -> Int'); do you want to add a stub?}}
+  // expected-note@+1 {{protocol requires subscript with type '(Wrapper<Base>.Index) -> Int' (aka '(Base.Index) -> Int'); add a stub for conformance}}
   subscript(position: Index) -> Int { get } 
 }