Simplify the ifdefs:

Simplify the ifdefs:
- fix this to compile with C++ by casting ints to enums in a few places
  and by using the correct parameter type for _fpsetprec().  Remove
  __cplusplus ifdefs which disabled the buggy code.
- remove __CC_SUPPORTS___INLINE ifdefs.  `__inline' vs `inline', and either
  of these #defined away, are supposed to be handled by very old ifdefs
  in <sys/cdefs.h>.  Thus the __CC_SUPPORTS___INLINE macro is not needed
  here (or anywhere else that it used).  It is less needed here than in
  most places, since this file is userland-only and userland is far from
  supporting INTEL_COMPILER.  The __CC_SUPPORTS___INLINE__ macro which
  was used here is even less needed.  It is to support spelling `inline'
  as `__inline__' instead of the usual spelling `__inline'.

Fix some style bugs that I missed in the previous commit (remove unused
asms and sort more variables).