[clang] [Parser][BoundsSafety] Print attribute as macro if it's system defined (PR #107619)

[Dan Liew via cfe-commits]

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@@ -0,0 +1,65 @@
+// RUN: %clang_cc1 -fsyntax-only -I%S/Inputs -Wthread-safety %s 2>&1 | FileCheck %s
+// RUN: %clang_cc1 -fsyntax-only -I%S/Inputs -Wthread-safety -std=c++98 %s 2>&1 | FileCheck %s
+// RUN: %clang_cc1 -fsyntax-only -I%S/Inputs -Wthread-safety -std=c++11 %s -D CPP11 2>&1 | FileCheck %s
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delcypher wrote:

@rapidsna Looks like there might be some missing test coverage here

* Late parsing isn't enabled in this test but the PR appears to be touching that code path
* There's no C version of this test that enables late parsing but this PR appears to be touching that code path.

https://github.com/llvm/llvm-project/pull/107619