[clang] [clang] Allow 'convergent' to be a statement attribute (PR #100637)

[via cfe-commits]

================
@@ -0,0 +1,99 @@
+// RUN: %clang_cc1 -emit-llvm %s -triple x86_64-unknown-linux-gnu -o - | FileCheck %s
----------------
darkbuck wrote:

I hacked `llvm/utils/UpdateTestChecks/common.py` a little bit to generate attribute def checks. I may ask for another review on that hack on update tools.

https://github.com/llvm/llvm-project/pull/100637