PR modula2/112946 set expression type checking

This patch adds type checking for binary set operators.
It also checks the IN operator and improves the := type checking.

gcc/m2/ChangeLog:

	PR modula2/112946
	* gm2-compiler/M2GenGCC.mod (IsExpressionCompatible): Import.
	(ExpressionTypeCompatible): Import.
	(CodeStatement): Remove op1, op2, op3 parameters from CodeSetOr,
	CodeSetAnd, CodeSetSymmetricDifference, CodeSetLogicalDifference.
	(checkArrayElements): Rename op1 to des and op3 to expr.
	Use despos and exprpos instead of CurrentQuadToken.
	(checkRecordTypes): Rename op1 to des and op2 to expr.
	Use virtpos instead of CurrentQuadToken.
	(checkIncorrectMeta): Ditto.
	(checkBecomes): Rename op1 to des and op3 to expr.
	Use virtpos instead of CurrentQuadToken.
	(NoWalkProcedure): New procedure stub.
	(CheckBinaryExpressionTypes): New procedure function.
	(CheckElementSetTypes): New procedure function.
	(CodeBinarySet): Re-write.
	(FoldBinarySet): Re-write.
	(CodeSetOr): Remove parameters op1, op2 and op3.
	(CodeSetAnd): Ditto.
	(CodeSetLogicalDifference): Ditto.
	(CodeSetSymmetricDifference): Ditto.
	(CodeIfIn): Call CheckBinaryExpressionTypes and
	CheckElementSetTypes.
	* gm2-compiler/M2Quads.mod (BuildRotateFunction): Correct
	parameters to MakeVirtualTok to reflect parameter block
	passed to Rotate.

gcc/testsuite/ChangeLog:

	PR modula2/112946
	* gm2/pim/fail/badbecomes.mod: New test.
	* gm2/pim/fail/badexpression.mod: New test.
	* gm2/pim/fail/badexpression2.mod: New test.
	* gm2/pim/fail/badifin.mod: New test.
	* gm2/pim/pass/goodifin.mod: New test.

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