Remove ENOSYS math/ function stubs.

Remove ENOSYS math/ function stubs.

The math/ directory has various stub implementations of functions
(generally long double functions, plus sqrtf128) that set errno to
ENOSYS and print a message.

These are a relic of when the long double libm implementation in glibc
was originally incomplete.  They are only present for a limited set of
libm functions, not all those that would need implementing for any
hypothetical new long double format, and only for long double (plus
sqrtf128), not for other floating-point types.  I removed the
corresponding ENOSYS tests in the testsuite in
<https://sourceware.org/ml/libc-alpha/2013-05/msg00599.html>.

I think these stubs are an inherently different case from stubs for
functionality needing OS-specific implementations, since
floating-point formats are generally standardized between modern
processors (a new long double format does not seem likely - I'd expect
new ports all to have long double = binary128 or long double =
binary64 - though _Float16 functions *f16 are entirely possible in
future) and libm functions are generally only expected to fail for
domain / range / pole errors, not for other unknown system-specific
conditions the way the functions needing OS-specific implementations
may fail.

This patch removes these stub implementations.  The effect (which, as
noted above, was actually mostly already the case, given the
incompleteness of the set of stubs, and was certainly the case if you
wanted your libm port to *work* rather than just build) is that any
new long double format needs to provide a full set of functions for
the build to succeed; any port using ldbl-128 needs to provide sqrtl
(possibly using the soft-fp version from another port); any port using
ldbl-96 needs to provide all those functions that all of
x86_64/i386/ia64/m68k provide rather than getting from the ldbl-96
directory; any port with _Float128 as a type with a distinct format
needs to provide sqrtf128.

Tested for x86_64.  Also tested with build-many-glibcs.py that
installed stripped shared libraries are unchanged by the patch.

	* math/e_acoshl.c: Remove.
	* math/e_acosl.c: Likewise.
	* math/e_asinl.c: Likewise.
	* math/e_atan2l.c: Likewise.
	* math/e_atanhl.c: Likewise.
	* math/e_coshl.c: Likewise.
	* math/e_expl.c: Likewise.
	* math/e_fmodl.c: Likewise.
	* math/e_gammal_r.c: Likewise.
	* math/e_hypotl.c: Likewise.
	* math/e_j0l.c: Likewise.
	* math/e_j1l.c: Likewise.
	* math/e_jnl.c: Likewise.
	* math/e_lgammal_r.c: Likewise.
	* math/e_log10l.c: Likewise.
	* math/e_log2l.c: Likewise.
	* math/e_logl.c: Likewise.
	* math/e_powl.c: Likewise.
	* math/e_rem_pio2l.c: Likewise.
	* math/e_sinhl.c: Likewise.
	* math/e_sqrtf128.c: Likewise.
	* math/e_sqrtl.c: Likewise.
	* math/k_cosl.c: Likewise.
	* math/k_sinl.c: Likewise.
	* math/k_tanl.c: Likewise.
	* math/s_asinhl.c: Likewise.
	* math/s_atanl.c: Likewise.
	* math/s_cbrtl.c: Likewise.
	* math/s_erfl.c: Likewise.
	* math/s_expm1l.c: Likewise.
	* math/s_log1pl.c: Likewise.
	* math/s_tanhl.c: Likewise.