[llvm] [MC][Support] Track macro definition locations for improved diagnostics (PR #198936)

[Fangrui Song via llvm-commits]

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@@ -0,0 +1,19 @@
+# RUN: not llvm-mc -triple x86_64 %s -o /dev/null 2>&1 | FileCheck %s
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MaskRay wrote:

Yeah - should just pre-commit this

https://github.com/llvm/llvm-project/pull/198936