[clang] [NFC][KeyInstr][Clang] Add some additional tests (PR #134654)

[Jeremy Morse via cfe-commits]

================
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -gkey-instructions -gno-column-info -x c++ %s -debug-info-kind=line-tables-only -emit-llvm -o -  \
+// RUN: | FileCheck %s --implicit-check-not atomGroup --implicit-check-not atomRank
+
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -gkey-instructions -gno-column-info -x c %s -debug-info-kind=line-tables-only -emit-llvm -o -  \
+// RUN: | FileCheck %s --implicit-check-not atomGroup --implicit-check-not atomRank
+
----------------
jmorse wrote:

A comment on what this test tries to cover would be good.

https://github.com/llvm/llvm-project/pull/134654