[clang] [PAC] Add support for __ptrauth type qualifier (PR #100830)

[Daniil Kovalev via cfe-commits]

================
@@ -2196,6 +2196,58 @@ Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
   return V;
 }
 
+static bool isDeclRefKnownNonNull(CodeGenFunction &CGF, const ValueDecl *D) {
+  return !D->isWeak();
+}
+
+static bool isLValueKnownNonNull(CodeGenFunction &CGF, const Expr *E) {
+  E = E->IgnoreParens();
+
+  if (auto *UO = dyn_cast<UnaryOperator>(E)) {
+    if (UO->getOpcode() == UO_Deref) {
+      return CGF.isPointerKnownNonNull(UO->getSubExpr());
+    }
+  }
+
+  if (auto *DRE = dyn_cast<DeclRefExpr>(E)) {
+    return isDeclRefKnownNonNull(CGF, DRE->getDecl());
+  } else if (auto *ME = dyn_cast<MemberExpr>(E)) {
+    if (isa<FieldDecl>(ME->getMemberDecl()))
+      return true;
+    return isDeclRefKnownNonNull(CGF, ME->getMemberDecl());
+  }
+
+  // Array subscripts?  Anything else?
+
+  return false;
+}
+
+bool CodeGenFunction::isPointerKnownNonNull(const Expr *E) {
+  assert(E->getType()->isSignableType());
+
+  E = E->IgnoreParens();
+
+  if (isa<CXXThisExpr>(E))
+    return true;
+
+  if (auto *UO = dyn_cast<UnaryOperator>(E)) {
----------------
kovdan01 wrote:

Nit
```suggestion
  if (const auto *UO = dyn_cast<UnaryOperator>(E))
```

https://github.com/llvm/llvm-project/pull/100830