+ 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
mark and sweep, stop the world garbage collector
(intermediate step in the way to ref counting).
can run pretty with an explicit gc after each file.
R=r
DELTA=502 (346 added, 143 deleted, 13 changed)
OCL=20630
CL=20635