Log Message:
move --disable-gcc-global-regs to Makefile.php.
Seems to make a previously segfaulting netbsd-8/i386's build not segfault.
ap-php runs PHP's configure and builds some of its code, so it needs the
same flag.

Now we can stop requiring an arbitrary GCC version. The test case in the
GCC bugzilla fails on all GCC versions I tested, but magically some
versions of GCC manage to build a working PHP.