[llvm] [llvm-objdump] Add triple support to `mcpu=help` (PR #165661)

[Ruoyu Qiu via llvm-commits]

================
@@ -14,3 +14,11 @@ FileHeader:
   Data:            ELFDATA2LSB
   Type:            ET_EXEC
   Machine:         EM_X86_64
+
+# RUN: llvm-objdump --triple=x86_64 --mcpu=help 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=CHECK-WITHOUT-DISASSEMBLING
+
+# CHECK-WITHOUT-DISASSEMBLING: Available CPUs for this target:
+# CHECK-WITHOUT-DISASSEMBLING: Available features for this target:
+
+; XFAIL: *
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cabbaken wrote:

It seems unlikely that a user would intend to call `--mcpu=help` in combination with `--section-headers` or `-d`.
Therefore, it would probably be best if the behavior of `--mcpu=help` remains consistent with `-h`.

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