Mark decls that are illegal due to generic inside non-generic decl or non-generic inside generic decl with setInvalid(), and avoid assertions

trying to set the superclass on classes in such situations by setting the superclass of an invalid decl to the error type.

This fixes a bunch of compiler crashes, and also changes some errors in other tests where the main error is the invalid declaration and now the
downstream errors can be a bit different because the decl has been invalidated.

Author: gregomni

lib/AST/Decl.cpp

@@ -4757,7 +4757,7 @@ Type TypeBase::getSwiftNewtypeUnderlyingType() {
 ClassDecl *ClassDecl::getSuperclassDecl() const {
   if (auto superclass = getSuperclass())
     return superclass->getClassOrBoundGenericClass();
-    return nullptr;
+  return nullptr;
 }
 
 void ClassDecl::setSuperclass(Type superclass) {

lib/Sema/ITCDecl.cpp

@@ -153,6 +153,8 @@ void IterativeTypeChecker::processTypeCheckSuperclass(
   }
 
   // Set the superclass type.
+  if (classDecl->isInvalid())
+    superclassType = ErrorType::get(getASTContext());
   classDecl->setSuperclass(superclassType);
 }
 

lib/Sema/TypeCheckDecl.cpp

@@ -3418,6 +3418,7 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
                       NTD->getName(),
                       proto->getName());
         }
+        NTD->setInvalid();
         return true;
       }
 
@@ -3432,6 +3433,7 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
                         diag::unsupported_type_nested_in_generic_type,
                         NTD->getName(),
                         parent->getName());
+          NTD->setInvalid();
           return true;
         } else if (auto ED = dyn_cast<ExtensionDecl>(DC)) {
           auto *parent = ED->getAsNominalTypeOrNominalTypeExtensionContext();

test/Parse/matching_patterns.swift

@@ -151,7 +151,7 @@ struct ContainsEnum {
 
   func member(_ n: Possible<Int>) {
     switch n {
-    case ContainsEnum.Possible<Int>.Naught,
+    case ContainsEnum.Possible<Int>.Naught, // expected-error{{cannot specialize a non-generic definition}} expected-note {{while parsing this '<' as a type parameter bracket}}
          ContainsEnum.Possible.Naught,
          Possible<Int>.Naught,
          Possible.Naught,
@@ -163,7 +163,7 @@ struct ContainsEnum {
 
 func nonmemberAccessesMemberType(_ n: ContainsEnum.Possible<Int>) {
   switch n {
-  case ContainsEnum.Possible<Int>.Naught,
+  case ContainsEnum.Possible<Int>.Naught, // expected-error{{cannot specialize a non-generic definition}} expected-note {{while parsing this '<' as a type parameter bracket}}
        .Naught:
     ()
   }

test/Parse/type_expr.swift

@@ -105,8 +105,8 @@ func genQualifiedType() {
   let _ : () = Gen<Foo>.Bar.meth()
   _ = Gen<Foo>.Bar.instMeth
 
-  _ = Gen<Foo>.Bar // expected-error{{expected member name or constructor call after type name}} expected-note{{add arguments}} {{19-19=()}} expected-note{{use '.self'}} {{19-19=.self}}
-  _ = Gen<Foo>.Bar.dynamicType // expected-error{{'.dynamicType' is not allowed after a type name}} {{20-31=self}}
+  _ = Gen<Foo>.Bar
+  _ = Gen<Foo>.Bar.dynamicType
 }
 
 func archetype<T: Zim>(_: T) {

test/decl/func/default-values.swift

@@ -48,9 +48,9 @@ struct Outer<T> {
     }
   }
 }
-Outer<Int>.Inner.VeryInner() // expected-warning{{unused}}
-Outer<Int>.Inner.VeryInner(i: 12) // expected-warning{{unused}}
-Outer<Int>.Inner.VeryInner(f:12.5) // expected-warning{{unused}}
+Outer<Int>.Inner.VeryInner()
+Outer<Int>.Inner.VeryInner(i: 12)
+Outer<Int>.Inner.VeryInner(f:12.5)
 Outer<Int>.Inner.VeryInner.f()
 Outer<Int>.Inner.VeryInner.f(i: 12)
 Outer<Int>.Inner.VeryInner.f(f:12.5)

test/decl/nested/type_in_type.swift

@@ -128,7 +128,7 @@ struct AnyStream<T : Sequence> {
   // Conform to the enumerable protocol.
   typealias Elements = StreamRange<T.Iterator>
   func getElements() -> Elements {
-    return Elements(index: 0, elements: input.makeIterator())
+    return Elements(index: 0, elements: input.makeIterator()) // expected-error {{'AnyStream<T>.StreamRange<T.Iterator>' cannot be constructed because it has no accessible initializers}}
   }
 }
 
@@ -177,7 +177,7 @@ extension Bar {
 class X6<T> {
   let d: D<T>
   init(_ value: T) {
-    d = D(value)
+    d = D(value) // expected-error{{'<<error type>>' cannot be constructed because it has no accessible initializers}}
   }
   class D<T2> { // expected-error{{generic type 'D' cannot be nested in type 'X6'}}
     init(_ value: T2) {}
@@ -203,7 +203,7 @@ struct GS<T> {
   struct NestedGeneric<U> { // expected-note{{generic type 'NestedGeneric' declared here}} // expected-error{{generic type 'NestedGeneric' cannot be nested in type 'GS'}}
     func fff() -> (GS, NestedGeneric) {
       let gs = GS()
-      let ns = NestedGeneric()
+      let ns = NestedGeneric() // expected-error {{'GS<T>.NestedGeneric<U>' cannot be constructed because it has no accessible initializers}}
       return (gs, ns)
     }
   }
@@ -245,7 +245,7 @@ func useNested(_ ii: Int, hni: HasNested<Int>,
   typealias InnerI = HasNested<Int>.Inner
   var innerI = InnerI(5)
   typealias InnerF = HasNested<Float>.Inner
-  var innerF : InnerF = innerI // expected-error{{cannot convert value of type 'InnerI' (aka 'HasNested<Int>.Inner') to specified type 'InnerF' (aka 'HasNested<Float>.Inner')}}
+  var innerF : InnerF = innerI
 
   _ = innerI.identity(i)
   i = innerI.identity(i)
@@ -265,6 +265,6 @@ func useNested(_ ii: Int, hni: HasNested<Int>,
   var ids = xis.g(1, u: "Hello", v: 3.14159)
   ids = (2, "world", 2.71828)
 
-  xis = xfs // expected-error{{cannot assign value of type 'HasNested<Float>.InnerGeneric<String>' to type 'HasNested<Int>.InnerGeneric<String>'}}
+  xis = xfs
 }
 

validation-test/compiler_crashers/28291-swift-constraints-constraintsystem-comparesolutions.swift renamed to validation-test/compiler_crashers_fixed/28291-swift-constraints-constraintsystem-comparesolutions.swift

@@ -5,6 +5,6 @@
 // See http://swift.org/LICENSE.txt for license information
 // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
-// RUN: not --crash %target-swift-frontend %s -parse
+// RUN: not %target-swift-frontend %s -parse
 // REQUIRES: asserts
 class T,struct A{func b{}struct A{class B<T}func b:A.B{var _=b<T

validation-test/compiler_crashers/28319-swift-typechecker-checkconformance.swift renamed to validation-test/compiler_crashers_fixed/28319-swift-typechecker-checkconformance.swift

@@ -5,6 +5,6 @@
 // See http://swift.org/LICENSE.txt for license information
 // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
-// RUN: not --crash %target-swift-frontend %s -parse
+// RUN: not %target-swift-frontend %s -parse
 // REQUIRES: asserts
 protocol A{enum B:A{let:e var _=B}typealias e

validation-test/compiler_crashers/28331-swift-createdesignatedinitoverride.swift renamed to validation-test/compiler_crashers_fixed/28331-swift-createdesignatedinitoverride.swift

@@ -5,5 +5,5 @@
 // See http://swift.org/LICENSE.txt for license information
 // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
-// RUN: not --crash %target-swift-frontend %s -parse
+// RUN: not %target-swift-frontend %s -parse
 let:{{class a{enum S<U:a{class B:a{init}}class a