detect broken linker handling of __ehdr_start

Older versions of ld on ia64 support __ehdr_start, but generate relocs
when they shouldn't.  This causes the ld.so to not run because it tries
to resolve the __ehdr_start symbol (but it's not exported).
Replace cpuid asm statement with __cpuid_count

The compiler doesn't know that the cpuid asm statement in intel_check_word
will trash RBX.  We are lucky that it doesn't cause any problems since
RBX is also used by compiler for other purposes so that RBX is saved and
restored.  This patch replaces it with __cpuid_count.

	[BZ #17259]
	* sysdeps/x86_64/cacheinfo.c (intel_check_word): Replace cpuid
	asm statement with __cpuid_count.
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