* libc/include/sys/config.h (__IEEE_LITTLE_ENDIAN)
(__IEEE_BIG_ENDIAN): Define appropriately for MIPS.
Check that one of them is defined and error out if not.
Add any platforms defined in <machine/ieeefp.h> that are missing.
* libc/search/hash.h (DB_BYTE_ORDER, DB_BIG_ENDIAN)
(DB_LITTLE_ENDIAN): New defines.
* libc/search/hash.c: Replace all incorrect checks for
_IEEE_LITTLE_ENDIAN with tests of BYTE_ORDER, and all uses of
BYTE_ORDER, LITTLE_ENDIAN, and BIG_ENDIAN with DB_* versions.
* libc/search/hash_page.c: Likewise.