[clang] do not abort on u8 string in inline asm (PR #177096)

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@@ -0,0 +1,7 @@
+// RUN: not %clang_cc1 -fsyntax-only -verify %s
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nataliakokoromyti wrote:

its just if we remove the not, then clang exits with 1, lit expects exit 0 --> test fails. lmk though if i should follow some other llvm pattern for how clang should handle this

https://github.com/llvm/llvm-project/pull/177096