modula2: tidyup gcc/m2/gm2-compiler/M2GenGCC.mod remove unused parameters/vars

modula2: tidyup gcc/m2/gm2-compiler/M2GenGCC.mod remove unused parameters/vars

This patch removes unused parameters and local variables from
M2GenGCC.mod.  It required ForeachScopeBlockDo2 to be implemented and
exported affecting any module indirectly calling ConvertQuadsToTree.

gcc/m2/ChangeLog:

	* gm2-compiler/M2BasicBlock.mod (InitBasicBlocks): Rename
	ForeachScopeBlockDo to ForeachScopeBlockDo3.
	* gm2-compiler/M2Code.mod: Import ForeachScopeBlockDo2.
	(OptimizeScopeBlock): Call ForeachScopeBlockDo3 for
	procedures with three parameters and ForeachScopeBlockDo2
	for two parameters.
	(CodeBlock): Ditto.
	* gm2-compiler/M2GCCDeclare.mod (DeclareTypesConstantsProcedures):
	Rename ForeachScopeBlockDo to ForeachScopeBlockDo3.
	* gm2-compiler/M2GenGCC.def (ConvertQuadsToTree): Remove Scope
	parameter.
	* gm2-compiler/M2GenGCC.mod (ConvertQuadsToTree): Remove Scope
	parameter.
	(MaybeDebugBuiltinMemcpy): Remove parameter tok.
	(MaybeDebugBuiltinMemset): Remove.
	(MakeCopyUse): Remove tokenno from call to
	MaybeDebugBuiltinMemcpy.
	(PerformFoldBecomes): Remove desloc and exprloc.
	(checkArrayElements): Remove location.  Remove virtpos
	as a parameter to MaybeDebugBuiltinMemcpy.
	(NoWalkProcedure): Add attribute unused.
	(CheckElementSetTypes): Remove parameter p.
	Remove CurrentQuadToken in call to MaybeDebugBuiltinMemcpy.
	Remove NoWalkProcedure from call to CheckElementSetTypes.
	Remove tokenno from call to MaybeDebugBuiltinMemcpy.
	* gm2-compiler/M2Optimize.mod (RemoveProcedures): Replace
	two parameter indirect procedure iterator with
	ForeachScopeBlockDo2.
	* gm2-compiler/M2SSA.mod: Remove ForeachScopeBlockDo.
	* gm2-compiler/M2Scope.def (ForeachScopeBlockDo2): New
	declaration.
	(ForeachScopeBlockDo): Rename ...
	(ForeachScopeBlockDo3): ... to this.
	(ScopeProcedure2): New declaration.
	* gm2-compiler/M2Scope.mod (ForeachScopeBlockDo2): New
	procedure.
	(ForeachScopeBlockDo): Rename ...
	(ForeachScopeBlockDo3): ... to this.

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