PR modula2/111675 Incorrect packed record field value passed to a procedure

PR modula2/111675 Incorrect packed record field value passed to a procedure

This patch allows a packed field to be extracted and passed to a
procedure.  It ensures that the subrange type is the same for both the
procedure and record field.  It also extends the <* bytealignment (0) *>
to cover packed subrange types.

gcc/m2/ChangeLog:

	PR modula2/111675
	* gm2-compiler/M2CaseList.mod (appendTree): Replace
	InitStringCharStar with InitString.
	* gm2-compiler/M2GCCDeclare.mod: Import AreConstantsEqual.
	(DeclareSubrange): Add zero alignment test and call
	BuildSmallestTypeRange if necessary.
	(WalkSubrangeDependants): Walk the align expression.
	(IsSubrangeDependants): Test the align expression.
	* gm2-compiler/M2Quads.mod (BuildStringAdrParam): Correct end name.
	* gm2-compiler/P2SymBuild.mod (BuildTypeAlignment): Allow subranges
	to be zero aligned (packed).
	* gm2-compiler/SymbolTable.mod (Subrange): Add Align field.
	(MakeSubrange): Set Align to NulSym.
	(PutAlignment): Assign Subrange.Align to align.
	(GetAlignment): Return Subrange.Align.
	* gm2-gcc/m2expr.cc (noBitsRequired): Rewrite.
	(calcNbits): Rename ...
	(m2expr_calcNbits): ... to this and test for negative values.
	(m2expr_BuildTBitSize): Replace calcNBits with m2expr_calcNbits.
	* gm2-gcc/m2expr.def (calcNbits): Export.
	* gm2-gcc/m2expr.h (m2expr_calcNbits): New prototype.
	* gm2-gcc/m2type.cc (noBitsRequired): Remove.
	(m2type_BuildSmallestTypeRange): Call m2expr_calcNbits.
	(m2type_BuildSubrangeType): Create range_type from
	build_range_type (type, lowval, highval).

gcc/testsuite/ChangeLog:

	PR modula2/111675
	* gm2/extensions/run/pass/packedrecord3.mod: New test.

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