hppa-linux-gnu-ranlib: libcpp.a: File format not recognized

hppa-linux-gnu-ranlib: libcpp.a: File format not recognized

This stops an --enable-targets selection affecting the main target in
regards to forcing 64-bit archives.  It also means mips64 and s390x
will revert to binutils-2.25 and binutils-2.26 behaviour of not
forcing 64-bit archives at least in the common case when plugins were
enabled.

	PR binutils/20464
	PR binutils/14625
	* configure.ac: Revert 2016-05-25 configure change setting
	want_64_bit_archive for mips64 and s390x.  Revise USE_64_BIT_ARCHIVE
	description.
	* configure: Regenerate.
	* config.in: Regenerate.