[CSDiagnostics] Use simplified locator to find owner type of a requirement failure

Only simplified locator points to the right underlying expression.

Resolves: rdar://116122902
(cherry picked from commit b3da15e)

Author: xedin

lib/Sema/CSDiagnostics.cpp

@@ -216,8 +216,7 @@ bool FailureDiagnostic::conformsToKnownProtocol(
 }
 
 Type RequirementFailure::getOwnerType() const {
-  auto anchor = getRawAnchor();
-
+  auto anchor = getAnchor();
   // If diagnostic is anchored at assignment expression
   // it means that requirement failure happened while trying
   // to convert source to destination, which means that

test/Generics/conditional_conformances.swift

@@ -353,7 +353,7 @@ func existential_good<T: P1>(_: T.Type) {
 }
 
 func existential_bad<T>(_: T.Type) {
-  _ = Free<T>() as P2 // expected-error{{protocol 'P2' requires that 'T' conform to 'P1'}}
+  _ = Free<T>() as P2 // expected-error{{generic struct 'Free' requires that 'T' conform to 'P1'}}
 }
 
 // rdar://problem/35837054

test/Generics/conditional_conformances_literals.swift

@@ -45,7 +45,7 @@ func arraySameType() {
 
     let _: SameType = arrayWorks as SameType
     let _: SameType = arrayFails as SameType
-    // expected-error@-1 {{protocol 'SameType' requires the types 'Fails' and 'Works' be equivalent}}
+    // expected-error@-1 {{generic struct 'Array' requires the types 'Fails' and 'Works' be equivalent}}
 }
 
 func dictionarySameType() {
@@ -70,7 +70,7 @@ func dictionarySameType() {
 
     let _: SameType = dictWorks as SameType
     let _: SameType = dictFails as SameType
-    // expected-error@-1 {{protocol 'SameType' requires the types 'Fails' and 'Works' be equivalent}}
+    // expected-error@-1 {{generic struct 'Dictionary' requires the types 'Fails' and 'Works' be equivalent}}
 }
 
 func arrayConforms() {
@@ -91,11 +91,11 @@ func arrayConforms() {
 
     let _: Conforms = [works] as Conforms
     let _: Conforms = [fails] as Conforms
-    // expected-error@-1 {{protocol 'Conforms' requires that 'Fails' conform to 'Conforms'}}
+    // expected-error@-1 {{generic struct 'Array' requires that 'Fails' conform to 'Conforms'}}
 
     let _: Conforms = arrayWorks as Conforms
     let _: Conforms = arrayFails as Conforms
-    // expected-error@-1 {{protocol 'Conforms' requires that 'Fails' conform to 'Conforms'}}
+    // expected-error@-1 {{generic struct 'Array' requires that 'Fails' conform to 'Conforms'}}
 }
 
 func dictionaryConforms() {
@@ -116,11 +116,11 @@ func dictionaryConforms() {
 
     let _: Conforms = [0 : works] as Conforms
     let _: Conforms = [0 : fails] as Conforms
-    // expected-error@-1 {{protocol 'Conforms' requires that 'Fails' conform to 'Conforms'}}
+    // expected-error@-1 {{generic struct 'Dictionary' requires that 'Fails' conform to 'Conforms'}}
 
     let _: Conforms = dictWorks as Conforms
     let _: Conforms = dictFails as Conforms
-    // expected-error@-1 {{protocol 'Conforms' requires that 'Fails' conform to 'Conforms'}}
+    // expected-error@-1 {{generic struct 'Dictionary' requires that 'Fails' conform to 'Conforms'}}
 }
 
 func combined() {
@@ -133,6 +133,6 @@ func combined() {
     // expected-error@-1 {{type 'any Conforms' cannot conform to 'Conforms'}} expected-note@-1 {{only concrete types such as structs, enums and classes can conform to protocols}}
 
     let _: Conforms = [[0: [1 : [fails]] as Conforms]]
-    // expected-error@-1 {{protocol 'Conforms' requires that 'Fails' conform to 'Conforms'}}
+    // expected-error@-1 {{generic struct 'Dictionary' requires that 'Fails' conform to 'Conforms'}}
     // expected-error@-2 {{type 'any Conforms' cannot conform to 'Conforms'}} expected-note@-2 {{only concrete types such as structs, enums and classes can conform to protocols}}
 }