[compiler-rt] [compiler-rt] Add cpu model init for Windows. (PR #111961)

[Martin Storsjö via llvm-commits]

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@@ -0,0 +1,42 @@
+#ifndef _ARM64_
+#define _ARM64_
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mstorsjo wrote:

That's interesting - I would generally expect it to work to include those headers as is, with the compiler default defines.

Can you boil that down to a standalone repro, with a file that just includes `<windows.h>` or similar (I guess the relevant one here is `<processthreadsapi.h>`)? Or is the case that `<processthreadsapi.h>` is one of the Windows headers that you can't include directly unless you've included `<windows.h>` first? In that case, I'd prefer including that first, rather than adding our own extra defines. (If you want to, you can define `WIN32_LEAN_AND_MEAN` to reduce the overhead of including the whole `<windows.h>`.)

https://github.com/llvm/llvm-project/pull/111961