[clang] [ARM] Introduce -mtp=auto and make it the default (PR #128728)

[via cfe-commits]

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@@ -42,4 +42,8 @@
 
 // RUN: %clang --target=armv7-linux -### -S %s 2>&1 | \
 // RUN: FileCheck -check-prefix=ARMv7_THREAD_POINTER_NON %s
-// ARMv7_THREAD_POINTER_NON-NOT: "-target-feature" "+read-tp-tpidruro"
+// ARMv7_THREAD_POINTER_NON: "-target-feature" "+read-tp-tpidruro"
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Zhenhang1213 wrote:

It‘s my fault, I want to set `+read-tp-tpidruro` by `-mtp=auto`

https://github.com/llvm/llvm-project/pull/128728