* aclocal.m4 (gcc_AC_C_CHARSET, gcc_AC_C_COMPILE_BIGENDIAN,
gcc_AC_C_FLOAT_FORMAT): New macros.
* configure.in: Add AC_PROG_CPP after CC tests;
gcc_AC_C_CHARSET and gcc_AC_C_FLOAT_FORMAT after the sizeof
tests; and gcc_AC_C_COMPILE_BIGENDIAN after gcc_AC_C_CHAR_BIT.
* configure, config.in: Regenerate.
* config.gcc: Remove references to deleted files.
(i370-*-opened*): Use i370/xm-mvs.h (which now defines only
FATAL_EXIT_CODE, which is the same between oe and mvs).