Merge commit '76424513dbb3' from apple/main into swift/next

Author: git apple-llvm automerger

clang/lib/Sema/SemaTemplateInstantiate.cpp

@@ -2696,7 +2696,10 @@ Sema::InstantiateClass(SourceLocation PointOfInstantiation,
 
     // BlockDecls can appear in a default-member-initializer. They must be the
     // child of a BlockExpr, so we only know how to instantiate them from there.
-    if (isa<BlockDecl>(Member))
+    // Similarly, lambda closure types are recreated when instantiating the
+    // corresponding LambdaExpr.
+    if (isa<BlockDecl>(Member) ||
+        (isa<CXXRecordDecl>(Member) && cast<CXXRecordDecl>(Member)->isLambda()))
       continue;
 
     if (Member->isInvalidDecl()) {

clang/test/SemaTemplate/explicit-instantiation.cpp

@@ -179,4 +179,10 @@ struct B : A<0> {
   virtual void foo() override; // expected-error{{declaration of 'foo' overrides a 'final' function}}
 };
 }
+
+template<typename T> struct LambdaInDefaultMemberInitInExplicitInstantiation {
+  int a = [this] { return a; }();
+};
+template struct LambdaInDefaultMemberInitInExplicitInstantiation<int>;
+LambdaInDefaultMemberInitInExplicitInstantiation<float> x;
 #endif

clang/test/SemaTemplate/instantiate-local-class.cpp

@@ -495,3 +495,12 @@ namespace PR45000 {
   void g() { f<int>(); }
   // expected-note@-1 {{in instantiation of default function argument expression for 'f<int>' required here}}
 }
+
+namespace LambdaInDefaultMemberInitializer {
+  template<typename T> void f() {
+    struct S {
+      void *p = [this] { return &p; }();
+    };
+  }
+  template void f<int>();
+}