Cleanup debugging code in libm

Cleanup debugging code in libm

David Das (das@) committed Bruce Evan's (bde's) WIP code for
expl() and logl() in git revision 25a4d6bfda29119.  That code
included instrumentation that allowed bde to generate pari
scripts used in testing/debugging.  This patch removes that
instrumentation as it is unlikely that others will ever use it.

* math/libm/msun/src/math_private.h:
  . Remove bde's macros for the generation of pari scripts.

* math/libm/msun/ld128/s_expl.c:
* math/libm/msun/ld128/s_logl.c:
* math/libm/msun/ld80/s_expl.c:
* math/libm/msun/ld80/s_logl.c:
  . Remove bde's DOPRINT_START macro.
  . Change RETURNP to RETURNF.
  . Change RETURN2P to RETURNF.  Adjust arguments as needed.
  . Change RETURNPI to RETURNI.
  . Change RETURN2PI to RETURNI.  Adjust arguments as needed.

PR:	272765
MFC after:	1 week