PR modula2/114517 gm2 does not allow comparison operator hash in column one

PR modula2/114517 gm2 does not allow comparison operator hash in column one

This patch allows -fno-cpp to be supplied to gm2.  Without this patch
it causes an ICE.  The patch allows -fno-cpp to turn off cpp flags.
These are tested in m2.flex to decide whether a change of state is
allowed (enabling handling of #line directives).

gcc/ChangeLog:

	PR modula2/114517
	* doc/gm2.texi: Mention gm2 treats a # in the first column
	as a preprocessor directive unless -fno-cpp is supplied.

gcc/m2/ChangeLog:

	PR modula2/114517
	* gm2-compiler/M2Options.def (SetCpp): Add comment.
	(GetCpp): Move after SetCpp.
	(GetLineDirectives): New procedure function.
	* gm2-compiler/M2Options.mod (GetLineDirectives): New
	procedure function.
	* gm2-gcc/m2options.h (M2Options_GetLineDirectives): New
	prototype.
	* gm2-lang.cc (gm2_langhook_init_options): OPT_fcpp only
	assert if !value.
	* m2.flex: Test GetLineDirectives before changing to LINE0
	state.

gcc/testsuite/ChangeLog:

	PR modula2/114517
	* gm2/cpp/fail/hashfirstcolumn2.mod: New test.
	* gm2/imports/fail/imports-fail.exp: New test.
	* gm2/imports/fail/localmodule2.mod: New test.
	* gm2/imports/run/pass/localmodule.mod: New test.

Signed-off-by: Gaius Mulley <(no_default)>