[clang] [CIR] Support single level Cleanup scope (PR #180276)

[Andy Kaylor via cfe-commits]

================
@@ -147,6 +149,21 @@ void *EHScopeStack::pushCleanup(CleanupKind kind, size_t size) {
 
   assert(!cir::MissingFeatures::innermostEHScope());
 
+  CIRGenBuilderTy &builder = cgf->getBuilder();
+  mlir::Location loc = builder.getUnknownLoc();
+  auto cleanupScope = cir::CleanupScopeOp::create(
+      builder, loc, cir::CleanupKind::All,
----------------
andykaylor wrote:

The CleanupKind flag should be set something like this:

```
if (isEHCleanup && cgf->getLangOpts()->Exceptions) {
  if (isNormalCleanup)
    cleanupKind = cir::CleanupKind::All;
  else
    cleanupKind = cir::CleanupKind::EH;
} else {
  if (isNormalCleanup)
    cleanupKind = cir::CleanupKind::Normal;
  else
    skipCleanup = true;
}
```
I intend `skipCleanup` here as a placeholder for the fact that if this is an EH-only and exceptions are disabled, or if it's a lifetime marker cleanup we shouldn't create a cleanup scope operation. The above should be reworked as needed. It's just a rough outline to represent the logic.

https://github.com/llvm/llvm-project/pull/180276