[clang] [clang-repl] Extend the C support. (PR #89804)

[Aaron Ballman via cfe-commits]

================
@@ -407,6 +406,16 @@ void IncrementalParser::CleanUpPTU(PartialTranslationUnit &PTU) {
       }
     }
   }
+
+  // FIXME: We should de-allocate MostRecentTU
+  for (Decl *D : MostRecentTU->decls()) {
+    if (!isa<NamedDecl>(D))
+      continue;
+    // Check if we need to clean up the IdResolver chain.
+    NamedDecl *ND = cast<NamedDecl>(D);
----------------
AaronBallman wrote:

```suggestion
    const auto *ND = dyn_cast<NamedDecl>(D);
    if (!ND)
      continue;
    // Check if we need to clean up the IdResolver chain.
```

https://github.com/llvm/llvm-project/pull/89804