For NEC 4100/4300 project: Add little endian support and misc cleanups.
* gencode.c (build_instruction): Use !ByteSwapMem instead of
BigEndianMem.
* interp.c (CONFIG, config_EP_{mask,shift,D,DxxDxx, config_BE): Delete.
(BigEndianMem): Rename to ByteSwapMem and change sense.
(BigEndianCPU, sim_write, LoadMemory, StoreMemory): Change
BigEndianMem references to !ByteSwapMem.
(set_endianness): New function, with prototype.
(sim_open): Call set_endianness.
(sim_info): Use simBE instead of BigEndianMem.
(xfer_direct_word, xfer_direct_long, swap_direct_word,
swap_direct_long, xfer_big_word, xfer_big_long, xfer_little_word,
xfer_little_long, swap_word, swap_long): Delete unnecessary MSC_VER
ifdefs, keeping the prototype declaration.
(swap_word): Rewrite correctly.
(ColdReset): Delete references to CONFIG. Delete endianness related
code; moved to set_endianness.