PR modula2/113730 Unexpected handling of mixed-precision integer arithmetic

This patch fixes a bug which occurs when an expression is created with
a ZType and an integer or cardinal.  The resulting subexpression is
incorrecly given a ZType which allows compatibility with another
integer/cardinal type.  The solution was to fix the subexpression
type.  In turn this required a minor change to SArgs.mod.

gcc/m2/ChangeLog:

	PR modula2/113730
	* gm2-compiler/M2Base.mod (IsUserType): New procedure function.
	(MixTypes): Use IsUserType instead of IsType before calling MixTypes.
	* gm2-compiler/M2GenGCC.mod (GetTypeMode): Remove and import from
	SymbolTable.
	(CodeBinaryCheck): Replace call to MixTypes with MixTypesBinary.
	(CodeBinary): Replace call to MixTypes with MixTypesBinary.
	(CodeIfLess): Replace MixTypes with ComparisonMixTypes.
	(CodeIfGre): Replace MixTypes with ComparisonMixTypes.
	(CodeIfLessEqu): Replace MixTypes with ComparisonMixTypes.
	(CodeIfGreEqu): Replace MixTypes with ComparisonMixTypes.
	(CodeIfEqu): Replace MixTypes with ComparisonMixTypes.
	(CodeIfNotEqu): Replace MixTypes with ComparisonMixTypes.
	(ComparisonMixTypes): New procedure function.
	* gm2-compiler/M2Quads.mod (BuildEndFor): Replace GenQuadO
	with GenQuadOtok and pass tokenpos for the operands to the AddOp
	and XIndrOp.
	(CheckRangeIncDec): Check etype against NulSym and dtype for a
	pointer and set etype to Address.
	(BuildAddAdrFunction): New variable opa.  Convert operand to an
	address and save result in opa.  Replace GenQuad with GenQuadOtok.
	(BuildSubAdrFunction): New variable opa.  Convert operand to an
	address and save result in opa.  Replace GenQuad with GenQuadOtok.
	(BuildDiffAdrFunction): New variable opa.  Convert operand to an
	address and save result in opa.  Replace GenQuad with GenQuadOtok.
	(calculateMultipicand): Replace GenQuadO with GenQuadOtok.
	(ConvertToAddress): New procedure function.
	(BuildDynamicArray): Convert index to address before adding to
	the base.
	* gm2-compiler/SymbolTable.def (GetTypeMode): New procedure function.
	* gm2-compiler/SymbolTable.mod (GetTypeMode): New procedure
	function implemented (moved from M2GenGCC.mod).
	* gm2-libs/SArgs.mod (GetArg): Replace cast to PtrToChar with ADDRESS.

gcc/testsuite/ChangeLog:

	PR modula2/113730
	* gm2/extensions/fail/arith1.mod: New test.
	* gm2/extensions/fail/arith2.mod: New test.
	* gm2/extensions/fail/arith3.mod: New test.
	* gm2/extensions/fail/arith4.mod: New test.
	* gm2/extensions/fail/arithpromote.mod: New test.
	* gm2/extensions/fail/extensions-fail.exp: New test.
	* gm2/linking/fail/badimp.def: New test.
	* gm2/linking/fail/badimp.mod: New test.
	* gm2/linking/fail/linking-fail.exp: New test.
	* gm2/linking/fail/testbadimp.mod: New test.

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