modula2: iso library SysClock.mod and wrapclock.cc fixes.

modula2: iso library SysClock.mod and wrapclock.cc fixes.

This patch corrects the C equivalent of m2 LONGINT parameters
in wrapclock.cc and corrects the SysClock.mod module.
wrapclock.cc uses a typedef long long int longint_t to match
m2 LONGINT (rather than unsigned long).  These fixes
prevent calls to SysClock hanging spinning on an (incorrect)
large day count from the epoch.

gcc/m2/ChangeLog:

	* gm2-compiler/M2Quads.mod (EndBuildFor): Improve
	block comments.
	* gm2-libs-iso/SysClock.mod (ExtractDate): Replace
	testDays with yearOfDays.  New local variable monthOfDays.

libgm2/ChangeLog:

	* libm2iso/wrapclock.cc (longint_t): New declaration.
	(GetTimespec): Replace types for sec and nano with
	longint_t.
	(SetTimespec): Replace types for sec and nano with
	longint_t.

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