[clang][Interp] Fix array element This chains

The previous test was too minimal. If we actually do something after
initializing the nested array element, we end up causing a stack element
type mismatch.

Author: tbaederr

clang/lib/AST/Interp/Compiler.cpp

@@ -92,7 +92,7 @@ bool InitLink::emit(Compiler<Emitter> *Ctx, const Expr *E) const {
   case K_Elem:
     if (!Ctx->emitConstUint32(Offset, E))
       return false;
-    return Ctx->emitArrayElemPtrUint32(E);
+    return Ctx->emitArrayElemPtrPopUint32(E);
   default:
     llvm_unreachable("Unhandled InitLink kind");
   }
@@ -4156,7 +4156,8 @@ bool Compiler<Emitter>::VisitCXXThisExpr(const CXXThisExpr *E) {
   if (InitStackActive && !InitStack.empty()) {
     unsigned StartIndex = 0;
     for (StartIndex = InitStack.size() - 1; StartIndex > 0; --StartIndex) {
-      if (InitStack[StartIndex].Kind != InitLink::K_Field)
+      if (InitStack[StartIndex].Kind != InitLink::K_Field &&
+          InitStack[StartIndex].Kind != InitLink::K_Elem)
         break;
     }
 

clang/test/AST/Interp/records.cpp

@@ -1551,8 +1551,12 @@ namespace ArrayInitChain {
 
   constexpr CustomOperandVal A[] = {
     {},
+    {{"depctr_hold_cnt"},  12,   13},
   };
   static_assert(A[0].Str.S == nullptr, "");
   static_assert(A[0].Width == 0, "");
   static_assert(A[0].Mask == 1, "");
+
+  static_assert(A[1].Width == 12, "");
+  static_assert(A[1].Mask == 13, "");
 }