[clang] [CIR] Handle NullStmt (PR #134889)

[Erich Keane via cfe-commits]

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@@ -90,3 +90,18 @@ int f3(void) {
 // OGCG-NEXT:   store i32 3, ptr %[[I_PTR]], align 4
 // OGCG-NEXT:   %[[I:.*]] = load i32, ptr %[[I_PTR]], align 4
 // OGCG-NEXT:   ret i32 %[[I]]
+
+// Verify null statement handling.
+void f4(void) {
+  ;
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erichkeane wrote:

The trailing one does.  The `{}` is a compound-stmt.  I notice in class-codegen we do some stuff to figure out if the `for` loop is empty (or `while` loop/etc) that checks it IIRC.  

https://github.com/llvm/llvm-project/pull/134889