Disable x87 inline functions for x86_64 and SSE [BZ #17262]

Since:

commit 409e00bd69b8d8dd74d7327085351d26769ea6fc
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Wed Jan 29 07:51:41 2014 -0800

    Disable x87 inline functions for SSE2 math

    When i386 and x86-64 mathinline.h was merged into a single mathinline.h,
    "gcc -m32" enables x87 inline functions on x86-64 even when -mfpmath=sse
    and SSE2 is enabled.  It is a regression on x86-64.  We should check
    __SSE2_MATH__ instead of __x86_64__ when disabling x87 inline functions.

gcc-3.2 is unable to correctly compile x86_64 routines for llrint
since it gets redefined.  This is because gcc 3.2 does not set
__SSE2_MATH__ for x86_64, thus exposing the duplicate definition.

The correct fix ought to be to check for both __SSE2_MATH__ and
__x86_64__ and enable those bits only when neither are defined.

Tested fix with the reproducer for
409e00bd69b8d8dd74d7327085351d26769ea6fc as well as with gcc-3.2.
Fix comment error that Jakub pointed out but I forgot to fix
Fix powerpc32 __get_clockfreq for non-power4 (bug 17263).

In my powerpc32 testing I've observed misc/test-gettimebasefreq
failing.

This is a glibc build (soft-float, though that's not relevant here)
without any --with-cpu and without any special configuration of the
default CPU for GCC either.  In particular, it's one not using
sysdeps/powerpc/powerpc32/power4/hp-timing.h (although in fact the
processor I'm using for testing is POWER4-based), so hp_timing_t is
32-bit not 64-bit.  But the VDSO call being used by
INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK is generating a 64-bit result
(high part in r3, low part in r4).  The code extracting that result,
however, expects a result of the type hp_timing_t as passed to
INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK, meaning that only r3 (= 0) is
used and the value in r4 is ignored.  This patch fixes this by always
using uint64_t as the type in INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK -
reflecting the actual ABI (unconditional in the kernel) of that VDSO
call.  This is the minimal change for this issue - no check for
overflow, no change of the type of the timebase_freq variable or the
return type of __get_clockfreq to something other than hp_timing_t
(such a change would simply move the implicit conversions to the over
callers of that function), no change to hp_timing_t itself.

Tested for powerpc32 soft float.

	[BZ #17263]
	* sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c: Include
	<stdint.h>.
	(__get_clockfreq): Use uint64_t instead of hp_timing_t in
	INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK call.
Mention fixes for BZs 16194 and 16275 in NEWS