Estimated hours taken: 1
Branches: release

Apply Zoltan's 2003/05/20 main branch patch to the release branch:

Fix several bugs in namespace cleanliness. These caused error messages, but
they were generated by the shell, not make, and thus didn't have the ** prefix,
which meant they were only spotten when someone happened to really look at
the relevant part of bootcheck output.

tools/bootcheck:
	Link *all* the RESERVED_MACRO_NAMES files into the stage2 directory,
	not just the one in runtime. Without this, all the namespace tests
	silently failed everywhere except in the runtime directory.

browser/RESERVED_MACRO_NAMES:
library/RESERVED_MACRO_NAMES:
	Add the macros defined by gcc and/or mgnuc to the permitted list,
	as was done for runtime/RESERVED_MACRO_NAMES a while ago.

trace/RESERVED_MACRO_NAMES:
	Add this file, which is a copy of the one in runtime, minus a macro
	that shouldn't be defined here. Without this file, one can't test
	namespace cleanliness of the trace directory even in stage 1.

library/io.m:
	Fix a namespace problem by adding an ML_ prefix.