Don't use alloca in addgetnetgrentX (BZ #16453)

addgetnetgrentX has a buffer which is grown as per the needs of the
requested size either by using alloca or by falling back to malloc if
the size is larger than 1K.  There are two problems with the alloca
bits: firstly, it doesn't really extend the buffer since it does not
use the return value of the extend_alloca macro, which is the location
of the reallocated buffer.  Due to this the buffer does not actually
extend itself and hence a subsequent write may overwrite stuff on the
stack.

The second problem is more subtle - the buffer growth on the stack is
discontinuous due to block scope local variables.  Combine that with
the fact that unlike realloc, extend_alloca does not copy over old
content and you have a situation where the buffer just has garbage in
the space where it should have had data.

This could have been fixed by adding code to copy over old data
whenever we call extend_alloca, but it seems unnecessarily
complicated.  This code is not exactly a performance hotspot (it's
called when there is a cache miss, so factors like network lookup or
file reads will dominate over memory allocation/reallocation), so this
premature optimization is unnecessary.

Thanks Brad Hubbard <bhubbard@redhat.com> for his help with debugging
the problem.
Mention addition of multiple precision fallback libm probes in NEWS
Fix math/test-fpucw-*.c for sysdeps test-fpucw.c overrides.

ARM has an override of the test math/test-fpucw.c, to disable (for
soft-float testing) definitions of hard-float macros in fpu_control.h
that the header normally defines not only when building for
hard-float, but also when building for soft-float with _LIBC defined
so that libc code can dynamically test whether VFP hardware is
present.  (_LIBC is defined when building tests, although ideally it
wouldn't be.)

The override doesn't work for the derived tests test-fpucw-*.c because
they use #include "" instead of <> to include test-fpucw.c, so always
get the math/ version instead of the ARM sysdeps override.  This patch
changes them to use <> so the sysdeps override is effective.
(test-fpucw-ieee-static.c doesn't need a change because it includes
test-fpucw-ieee.c, which isn't itself being overridden, which in turn
includes test-fpucw.c with a #include changed by this patch.)

Tested for ARM (big-endian soft-float, non-VFP hardware).

	* math/test-fpucw-ieee.c: Use <> in #include of test-fpucw.c.
	* math/test-fpucw-static.c: Likewise.
PowerPC: Fix ftime gettimeofday internal call returning bogus data

This patches fixes BZ#16430 by setting a different symbol for internal
GLIBC calls that points to ifunc resolvers. For PPC32, if the symbol
is defined as hidden (which is the case for gettimeofday and time) the
compiler will create local branches (symbol@local) and linker will not
create PLT calls (required for IFUNC). This will leads to internal symbol
calling the IFUNC resolver instead of the resolved symbol.
For PPC64 this behavior does not occur because a call to a function in
another translation unit might use a different toc pointer thus requiring
a PLT call.
Add BZ#16430 to NEWS.
s390: implement sotruss support

See commit 41b1792698a335d3a85381921a84a16e9635f36a for testcase.

Note: while this works on s390x, the s390 code hangs when using -e.
But it hangs regardless of this code (the hang seems to occur before
the exit func is even called).  I didn't look too closely at it as
it seems to be an issue external to this file, so this code shouldn't
make the situation any worse.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>