go: incorporate compiler and asm tool flags into compile cache key

[tdyas]

#14661 did not add compiler options as part of the cache key since some amount of tracing values in go's logic was still necessary. This issue covers doing that work.

• Compiler options added by https://github.com/golang/go/blob/21998413ad82655fef1f31316db31e23e0684b21/src/cmd/go/internal/work/exec.go#L314.
• Asm options added by https://github.com/golang/go/blob/21998413ad82655fef1f31316db31e23e0684b21/src/cmd/go/internal/work/exec.go#L316

[stuhood]

The go tool version not ending up in the cache key makes sense, because it is provided via a path rather than a digest. But it's not clear how other values would not end up as part of the process's digest: are they not part of the input files?

[tdyas]

The go tool version not ending up in the cache key makes sense, because it is provided via a path rather than a digest. But it's not clear how other values would not end up as part of the process's digest: are they not part of the input files?

GOOS and GOARCH, for example, would not be part of the cache key, unless they had been set explicitly in the environment.

That said, some of the logic related to incorporating command-line options is unnecessary since they are part of the Command proto. But that part of the algorithm was not adopted by #14661 in any event.

[stuhood]

GOOS and GOARCH, for example, would not be part of the cache key, unless they had been set explicitly in the environment.

I think that that could be addressed by setting Process.platform_constraint for go executions, since that is included in the cache key here:

pants/src/rust/engine/process_execution/src/remote.rs

Lines 941 to 951 in ed4d01e

	{
	command
	.environment_variables
	.push(remexec::command::EnvironmentVariable {
	name: CACHE_KEY_TARGET_PLATFORM_ENV_VAR_NAME.to_string(),
	value: match req.platform_constraint {
	Some(plat) => plat.into(),
	None => "none".to_string(),
	},
	});
	}