Remove dead code from old-and-crufty compatibility macros.
In particular these configure macros: HAVE_NQNFS_LEASES (no
one runs 10.3 MacOSX), HAVE_SGIDEFS_H, HAVE_ABI_MUTEX_H (no
IRIX anymore), HAVE_IOSTREAM_H, HAVE_IOSTREAM (no C++ code
in core PCP anymore).
Remove dead code from old-and-crufty compatibility macros.
In particular these configure macros: HAVE_NQNFS_LEASES (no
one runs 10.3 MacOSX), HAVE_SGIDEFS_H, HAVE_ABI_MUTEX_H (no
IRIX anymore), HAVE_IOSTREAM_H, HAVE_IOSTREAM (no C++ code
in core PCP anymore).