Regenerate x86_64, x86 ulps from scratch.

The x86_64 and x86 libm-test-ulps files hadn't been regenerated from
scratch for some time, as evidenced by the presence of entries for
*_tonearest functions (those tests duplicated the
default-rounding-mode tests, and such duplicates are no longer run).
The aarch64, alpha, hppa, ia64, m68k, microblaze, powerpc, s390, sh,
sparc, tile files similarly could do with from-scratch regeneration as
evidenced by the presence of such entries.  (Truncate the existing
file then run "make regen-ulps" and move the resulting file into
place.)

This patch regenerates the x86_64 and x86 files from scratch.  It's
likely some of the reduced / removed ulps will need restoring because
they appear on processors or compiler versions other than the one I
tested on, but in such cases I'd like to first see if I can generate
new tests that show such ulps on the Intel processor I'm testing on,
to reduce the effects from different people using different processors
and compilers to regenerate the ulps.

	* sysdeps/i386/fpu/libm-test-ulps: Regenerated.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.