cmd/compile: rework TestPGOHash to not rebuild dependencies
TestPGOHash may rebuild dependencies as we pass -trimpath to the
go command. This CL makes it pass -trimpath compiler flag to only
the current package instead, as we only need the current package
to have a stable source file path.
Also refactor buildPGOInliningTest to only take compiler flags,
not go flags, to avoid accidental rebuild.
Should fix #63733.
Change-Id: Iec6c4e90cf659790e21083ee2e697f518234c5b9
Reviewed-on: https://go-review.googlesource.com/c/go/+/535915 Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Bryan Mills <bcmills@google.com>