[clang] [Clang] Use ExtWarn for static local variable in extern inline function (fixes #39524) (PR #166332)

[Aaron Ballman via cfe-commits]

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+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -std=c11 -pedantic-errors -verify %s
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AaronBallman wrote:

I don't think the test should have a triple; I would expect this diagnostic to be target-agnostic based on the code which emits the diagnostic. Can you hook up a debugger to see why the diagnostic was being silenced on Windows targets in the first place?

https://github.com/llvm/llvm-project/pull/166332