Tweak code to make it easier to compile with gcc.

Tweak code to make it easier to compile with gcc.
  + Use macros to name symbols with non-ASCII characters.
  + Make some variables unsigned, because they are compared
    against unsigned values.
  + Fix a few void* pointers to be MLink*.

R=rsc
DELTA=94  (44 added, 3 deleted, 47 changed)
OCL=22303
CL=22638