[clang] `__noop` not marked as constexpr #102064 (PR #105983)

[via cfe-commits]

================
@@ -0,0 +1,3 @@
+// RUN: %clang_cc1 -std=c++20 -fms-extensions %s
+// expected-no-diagnostics
+constexpr int x = []{ __noop; return 0; }();
----------------
ofAlpaca wrote:

@cor3ntin 
I have added this test to builtins.cpp.
I'm not sure if this is a good way to add this test.
Please have a look. Thanks!

https://github.com/llvm/llvm-project/pull/105983