* mn10200-tdep.c: Remove lots of debugging printfs, update/improve

    * mn10200-tdep.c: Remove lots of debugging printfs, update/improve
        comments, formatting, etc.  Plus other minor fixes for problems
        I found during my first pass over the mn10200 port.
        (mn10200_analyze_prologue): New function.
        (mn10200_frame_chain, mn10200_init_extra_frame_info): Use it.
        * config/mn10200/tm-mn10200.h: Lots of updates/improvements to
        comments, formatting, etc.  Minor fixes for problems I found during
        my first pass over the mn10200 port.
        (TARGET_*_BIT): Define appropriately for ints, long longs, doubles and
        pointers.
        (REGISTER_VIRTUAL_TYPE): Define as a long.
        (EXTRACT_RETURN_VALUE): Rework to deal with long ints living
        in register pairs.
        (STORE_RETURN_VALUE): Similarly.
Checking in my initial changes, prologue scanning, etc.
Current gdb testsuite results:

                === gdb Summary ===

# of expected passes       3684
# of expected failures     40
# of unexpected failures   6