cmd/compile/internal/amd64: disable FIPS 140-3 mode for TestGoAMD64v1

cmd/compile/internal/amd64: disable FIPS 140-3 mode for TestGoAMD64v1

TestGoAMD64v1 modifies the binary, which will make the FIPS 140-3
integrity self-check fail. Disable FIPS 140-3 mode when running the
modified binary.

Change-Id: I6a6a46566a38f8c44f996f6e1155dac5f67c56e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/658915
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>