Avoid local PLT reference in __nptl_main.
Don't use INTDEF with __ldexpf (bug 14132).

Continuing the removal of the obsolete INTDEF / INTUSE mechanism, this
patch removes the use of INTDEF for __ldexpf.  As far as I can tell,
the resulting alias is completely unused.

Tested for x86_64 that stripped installed shared libraries are
unchanged by this patch.

	[BZ #14132]
	* math/s_ldexpf.c (__ldexpf): Do not use INTDEF.