LP64_ARCHS didn't work (GO_ARCHS/LP64_ARCHS aren't available until after the mk files are pulled in which cause ONLY_FOR_ARCHS to be checked) so just hardcode amd64 instead.
LP64_ARCHS didn't work (GO_ARCHS/LP64_ARCHS aren't available until after the mk files are pulled in which cause ONLY_FOR_ARCHS to be checked) so just hardcode amd64 instead.