[modula2] Bugfix local symbol names for -fm2-whole-program

Local symbols must be prefixed by the modulename if
-fm2-whole-program is used to avoid a name clash.

gcc/m2/ChangeLog:

	* gm2-compiler/M2AsmUtil.mod (SymNeedsModulePrefix):
	Re-implemented.
	* gm2-libs/SysStorage.mod (enableTrace): Disable tracing.

Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>