[clang] [CIR] Handle FunctionToPointerDecay casts (#153657) (PR #154060)

[Morris Hafner via cfe-commits]

================
@@ -73,21 +73,59 @@ Address CIRGenFunction::emitPointerWithAlignment(const Expr *expr,
 
   // Casts:
   if (auto const *ce = dyn_cast<CastExpr>(expr)) {
-    if (isa<ExplicitCastExpr>(ce)) {
-      cgm.errorNYI(expr->getSourceRange(),
-                   "emitPointerWithAlignment: explicit cast");
-      return Address::invalid();
-    }
+    if (const auto *ece = dyn_cast<ExplicitCastExpr>(ce))
+      cgm.emitExplicitCastExprType(ece);
 
     switch (ce->getCastKind()) {
     // Non-converting casts (but not C's implicit conversion from void*).
     case CK_BitCast:
     case CK_NoOp:
     case CK_AddressSpaceConversion: {
-      cgm.errorNYI(expr->getSourceRange(),
-                   "emitPointerWithAlignment: noop cast");
-      return Address::invalid();
-    } break;
+      if (const auto *ptrTy =
+              ce->getSubExpr()->getType()->getAs<PointerType>()) {
+        if (ptrTy->getPointeeType()->isVoidType())
+          break;
+
+        LValueBaseInfo innerBaseInfo;
----------------
mmha wrote:

```suggestion
        LValueBaseInfo innerBaseInfo;
        assert(!cir::MissingFeatures::opTBAA());
```

https://github.com/llvm/llvm-project/pull/154060