* 4.1 stays the active version because 4.2.1 still doesn't behave correctly with parallel builds.
Also revert an upstream commit until a real fix is available, just like Gentoo did with 4.2-r1. See https://bugs.gentoo.org/583812 (This was blocking "haikuporter --test make-4.2".) Finally, remove unneeded call to libtoolize.