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

[Aaron Ballman via cfe-commits]

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@@ -0,0 +1,4 @@
+#pragma clang system_header
+
+#define _SYS_NODEREF __attribute__((noderef))
+#define _SYS_LIBCPP_FLOAT_ABI __attribute__((pcs("aapcs")))
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AaronBallman wrote:

Please also have tests using `__declspec` and `[[]]` style attributes as well.

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