[clang] [llvm] [clang] Add cc1 --output-asm-variant= to set output syntax (PR #109360)

[Fangrui Song via llvm-commits]

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@@ -7209,6 +7209,9 @@ def fuse_ctor_homing: Flag<["-"], "fuse-ctor-homing">,
 def as_secure_log_file : Separate<["-"], "as-secure-log-file">,
   HelpText<"Emit .secure_log_unique directives to this filename.">,
   MarshallingInfoString<CodeGenOpts<"AsSecureLogFile">>;
+def output_asm_variant : Joined<["--"], "output-asm-variant=">,
+  HelpText<"Select the asm variant (integer) to use for output">,
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MaskRay wrote:

Agreed with the conservation. The ergonomics is one the reasons that this option is kept internal (cl::opt, cc1, not driver).

llvm-mc and llc currently use output-asm-variant=1 and the integer looks better for non-x86 targets.

https://github.com/llvm/llvm-project/pull/109360