[clang] [Clang][Modules] Emit C++20 BMIs to working directory with -fmodule-output (PR #174560)

[Chuanqi Xu via cfe-commits]

================
@@ -51,7 +51,7 @@
 
 // RUN: %clang -std=c++20 Hello.cppm --precompile -fmodules-reduced-bmi \
 // RUN:     -### 2>&1 | FileCheck Hello.cppm \
-// RUN:     --check-prefix=CHECK-OVERRIDE-WARN
+// RUN:     --check-prefix=CHECK-OVERRIDE-WARN-NOT
----------------
ChuanqiXu9 wrote:

If it is the case, we need another test to check the warning.

https://github.com/llvm/llvm-project/pull/174560