[clang] [clang][AArch64] Add validation for Global Register Variable. (PR #94271)

[KAWASHIMA Takahiro via cfe-commits]

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@@ -0,0 +1,13 @@
+// Check that -ffixed register handled for globals.
+// Regression test for #76426
+// RUN: %clang --target=aarch64-none-gnu -ffixed-x15 -### %s 2>&1 | FileCheck %s
+// CHECK-NOT: fatal error: error in backend: Invalid register name "x15".
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kawashima-fj wrote:

You modified Clang code but this error message is the one of the LLVM backend.
Is it better to check the Clang-side message `error: size of register 'x15' does not match variable size`?

https://github.com/llvm/llvm-project/pull/94271