[llvm] [PowerPC] Utilize `getReservedRegs` to find asm clobberable registers. (PR #99766)

[via llvm-commits]

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@@ -1,7 +1,7 @@
 ; RUN: llc < %s -verify-machineinstrs -mtriple=powerpc-unknown-unkown \
-; RUN:   -mcpu=pwr7 2>&1 | FileCheck %s
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EsmeYi wrote:

The purpose is to avoid optimizing the clobbering of r30 and r31 in @test_r31_r30_clobber().

https://github.com/llvm/llvm-project/pull/99766