[clang][Interp] Fix init chain in local initializers

Author: tbaederr

clang/lib/AST/Interp/Compiler.cpp

@@ -3577,6 +3577,7 @@ VarCreationState Compiler<Emitter>::visitVarDecl(const VarDecl *VD, bool Topleve
     return !Init || (checkDecl() && initGlobal(*GlobalIndex));
   } else {
     VariableScope<Emitter> LocalScope(this, VD);
+    InitLinkScope<Emitter> ILS(this, InitLink::Decl(VD));
 
     if (VarT) {
       unsigned Offset = this->allocateLocalPrimitive(
@@ -3911,7 +3912,8 @@ bool Compiler<Emitter>::VisitCXXDefaultInitExpr(const CXXDefaultInitExpr *E) {
   SourceLocScope<Emitter> SLS(this, E);
 
   bool Old = InitStackActive;
-  InitStackActive = !isa<FunctionDecl>(E->getUsedContext());
+  InitStackActive =
+      !(E->getUsedContext()->getDeclKind() == Decl::CXXConstructor);
   bool Result = this->delegate(E->getExpr());
   InitStackActive = Old;
   return Result;

clang/test/AST/Interp/records.cpp

@@ -1482,3 +1482,15 @@ namespace FloatAPValue {
   ClassTemplateArgRefTemplate<ClassTemplateArgObj.Arg> ClassTemplateArgRefObj;
 }
 #endif
+
+namespace LocalWithThisPtrInit {
+  struct S {
+    int i;
+    int *p = &i;
+  };
+  constexpr int foo() {
+    S s{2};
+    return *s.p;
+  }
+  static_assert(foo() == 2, "");
+}