[clang][bytecode] Narrow pointer in UO_Deref unary operators (#113089)

Otherwise we treat this like an array element even though we should
treat it as a single object.

Author: tbaederr

clang/lib/AST/ByteCode/Compiler.cpp

@@ -5738,9 +5738,17 @@ bool Compiler<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
     // We should already have a pointer when we get here.
     return this->delegate(SubExpr);
   case UO_Deref: // *x
-    if (DiscardResult)
+    if (DiscardResult) {
+      // assert(false);
       return this->discard(SubExpr);
-    return this->visit(SubExpr);
+    }
+
+    if (!this->visit(SubExpr))
+      return false;
+    if (classifyPrim(SubExpr) == PT_Ptr)
+      return this->emitNarrowPtr(E);
+    return true;
+
   case UO_Not: // ~x
     if (!T)
       return this->emitError(E);

clang/lib/AST/ByteCode/Pointer.cpp

@@ -635,7 +635,7 @@ std::optional<APValue> Pointer::toRValue(const Context &Ctx,
 
   // Return the composite type.
   APValue Result;
-  if (!Composite(getType(), *this, Result))
+  if (!Composite(ResultType, *this, Result))
     return std::nullopt;
   return Result;
 }

clang/test/AST/ByteCode/cxx98.cpp

@@ -54,3 +54,8 @@ _Static_assert(a == 0, ""); // both-error {{static assertion expression is not a
 struct SelfReference { SelfReference &r; };
 extern SelfReference self_reference_1;
 SelfReference self_reference_2 = {self_reference_1};
+
+struct PR65784s{
+  int *ptr;
+} const PR65784[] = {(int *)""};
+PR65784s PR65784f() { return *PR65784; }