[llvm] [llvm-objdump] Support --mcpu=help/--mattr=help without -d (PR #165661)

[James Henderson via llvm-commits]

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@@ -0,0 +1,25 @@
+# RUN: yaml2obj %s -o %t
+# REQUIRES: mips-registered-target,x86-registered-target
+
+## We shoule be able to retrieve help message by triple.
+# RUN: llvm-objdump --mattr=help --triple=mips 2>&1 \
+# RUN:   | FileCheck %s --check-prefixes=CHECK-HELP,CHECK-MIPS
+# RUN: llvm-objdump --mcpu=help --triple=mips 2>&1 \
+# RUN:   | FileCheck %s --check-prefixes=CHECK-HELP,CHECK-MIPS
+
+## The help message will always depends on --triple.
----------------
jh7370 wrote:

```suggestion
## The help message will depend on the target specified by --triple even if the input is for a different target.
```

https://github.com/llvm/llvm-project/pull/165661