PR modula2/115328 The FORWARD keyword is not implemented

This patch implements the FORWARD keyword found in the ISO standard.
The patch checks incoming parameters against the prior declaration
found in definition/forward sections and will issue an error based
on virtual tokens highlighing the full parameter declaration.

gcc/m2/ChangeLog:

	PR modula2/115328
	* gm2-compiler/M2MetaError.def: Extend comment documentating
	new format specifiers.
	* gm2-compiler/M2MetaError.mod (GetTokProcedure): New declaration.
	(doErrorScopeModule): New procedure.
	(doErrorScopeForward): Ditto.
	(doErrorScopeMod): Reimplement.
	(doErrorScopeFor): New procedure.
	(declarationMod): Ditto.
	(doErrorScopeDefinition): Ditto.
	(doErrorScopeDef): Reimplement.
	(declaredDef): New procedure.
	(declaredFor): Ditto.
	(doErrorScopeProc): Ditto.
	(declaredVar): Ditto.
	(declaredType): Ditto.
	(declaredFull): Ditto.
	* gm2-compiler/M2Options.mod (SetAutoInit): Add missing
	return type.
	(GetDumpGimple): Remove duplicate implementation.
	* gm2-compiler/M2Quads.def (DupFrame): New procedure.
	* gm2-compiler/M2Quads.mod (DupFrame): New procedure.
	* gm2-compiler/M2Reserved.def (ForwardTok): New variable.
	* gm2-compiler/M2Reserved.mod (ForwardTok): Initialize variable.
	* gm2-compiler/M2Scaffold.mod (DeclareArgEnvParams): Add
	tokno parameter for call to PutParam.
	* gm2-compiler/P0SymBuild.def (EndForward): New procedure.
	* gm2-compiler/P0SymBuild.mod (EndForward): New procedure.
	* gm2-compiler/P0SyntaxCheck.bnf (BlockAssert): New procedure.
	(ProcedureDeclaration): Reimplement rule.
	(PostProcedureHeading): New rule.
	(ForwardDeclaration): Ditto.
	(ProperProcedure): Ditto.
	* gm2-compiler/P1Build.bnf (ProcedureDeclaration): Reimplement rule.
	(PostProcedureHeading): New rule.
	(ForwardDeclaration): Ditto.
	(ProperProcedure): Ditto.
	* gm2-compiler/P1SymBuild.def (Export): Removed unnecessary
	export.
	(EndBuildForward): New procedure.
	* gm2-compiler/P1SymBuild.mod (StartBuildProcedure): Reimplement.
	(EndBuildProcedure): Ditto.
	(EndBuildForward): Ditto.
	* gm2-compiler/P2Build.bnf (ProcedureDeclaration): Reimplement rule.
	(PostProcedureHeading): New rule.
	(ForwardDeclaration): Ditto.
	(ProperProcedure): Ditto.
	* gm2-compiler/P2SymBuild.def (BuildProcedureDefinedByForward):
	New procedure.
	(BuildProcedureDefinedByProper): Ditto.
	(CheckProcedure): Ditto.
	(EndBuildForward): Ditto.
	* gm2-compiler/P2SymBuild.mod (EndBuildProcedure): Reimplement.
	(EndBuildForward): New procedure.
	(BuildFPSection): Reimplement to allow forward declaration or
	checking of parameters.
	(BuildProcedureDefinedByProper): New procedure.
	(BuildProcedureDefinedByForward): Ditto
	(FailParameter): Remove.
	(ParameterError): New procedure.
	(ParameterMismatch): Ditto.
	(EndBuildFormalParameters): Add parameter number check.
	(GetComparison): New procedure function.
	(GetSourceDesc): Ditto.
	(GetCurSrcDesc): Ditto.
	(GetDeclared): New procedure.
	(ReturnTypeMismatch): Ditto.
	(BuildFunction): Reimplement.
	(CheckProcedure): New procedure.
	(CheckFormalParameterSection): Reimplement using ParameterError.
	* gm2-compiler/P3Build.bnf (ProcedureDeclaration): Reimplement rule.
	(PostProcedureHeading): New rule.
	(ForwardDeclaration): Ditto.
	(ProperProcedure): Ditto.
	* gm2-compiler/P3SymBuild.def (Export): Remove unnecessary export.
	(EndBuildForward): New procedure.
	* gm2-compiler/P3SymBuild.mod (EndBuildForward): New procedure.
	* gm2-compiler/PCBuild.bnf (ProcedureDeclaration): Reimplement rule.
	(PostProcedureHeading): New rule.
	(ForwardDeclaration): Ditto.
	(ProperProcedure): Ditto.
	* gm2-compiler/PCSymBuild.def (EndBuildForward): New procedure.
	* gm2-compiler/PCSymBuild.mod (EndBuildForward): Ditto.
	* gm2-compiler/PHBuild.bnf (ProcedureDeclaration): Reimplement rule.
	(PostProcedureHeading): New rule.
	(ForwardDeclaration): Ditto.
	(ProperProcedure): Ditto.
	* gm2-compiler/SymbolTable.def (PutVarTok): New procedure.
	(PutParam): Add typetok parameter.
	(PutVarParam): Ditto.
	(PutParamName): Ditto.
	(GetDeclaredFor): New procedure function.
	(AreParametersDefinedInDefinition): Ditto.
	(PutParametersDefinedByForward): New procedure.
	(GetParametersDefinedByForward): New procedure function.
	(PutParametersDefinedByProper): New procedure.
	(GetParametersDefinedByProper): New procedure function.
	(GetProcedureDeclaredForward): Ditto.
	(PutProcedureDeclaredForward): New procedure.
	(GetProcedureDeclaredProper): New procedure function.
	(PutProcedureDeclaredProper): New procedure.
	(GetProcedureDeclaredDefinition): New procedure function.
	(PutProcedureDeclaredDefinition): New procedure.
	(GetVarDeclTypeTok): Ditto.
	(PutVarDeclTypeTok): New procedure.
	(GetVarDeclTok): Ditto.
	(PutVarDeclTok): New procedure.
	(GetVarDeclFullTok): Ditto.
	* gm2-compiler/SymbolTable.mod (ProcedureDecl): New record type.
	(VarDecl): Ditto.
	(SymProcedure): Add new field Declared.
	(SymVar): Add new field Declared.
	(PutVarTok): New procedure.
	(PutParam): Add typetok parameter.
	(PutVarParam): Ditto.
	(PutParamName): Ditto.
	(GetDeclaredFor): New procedure function.
	(AreParametersDefinedInDefinition): Ditto.
	(PutParametersDefinedByForward): New procedure.
	(GetParametersDefinedByForward): New procedure function.
	(PutParametersDefinedByProper): New procedure.
	(GetParametersDefinedByProper): New procedure function.
	(GetProcedureDeclaredForward): Ditto.
	(PutProcedureDeclaredForward): New procedure.
	(GetProcedureDeclaredProper): New procedure function.
	(PutProcedureDeclaredProper): New procedure.
	(GetProcedureDeclaredDefinition): New procedure function.
	(PutProcedureDeclaredDefinition): New procedure.
	(GetVarDeclTypeTok): Ditto.
	(PutVarDeclTypeTok): New procedure.
	(GetVarDeclTok): Ditto.
	(PutVarDeclTok): New procedure.
	(GetVarDeclFullTok): Ditto.
	(MakeProcedure): Initialize Declared field.
	(MakeVar): Initialize Declared field.
	* gm2-libs-log/FileSystem.def (FileNameChar): Add
	missing return type.
	* m2.flex: Add FORWARD keyword.

gcc/testsuite/ChangeLog:

	PR modula2/115328
	* gm2/iso/fail/badparam.def: New test.
	* gm2/iso/fail/badparam.mod: New test.
	* gm2/iso/fail/badparam2.def: New test.
	* gm2/iso/fail/badparam2.mod: New test.
	* gm2/iso/fail/badparam3.def: New test.
	* gm2/iso/fail/badparam3.mod: New test.
	* gm2/iso/fail/badparamarray.def: New test.
	* gm2/iso/fail/badparamarray.mod: New test.
	* gm2/iso/fail/simpledef1.def: New test.
	* gm2/iso/fail/simpledef1.mod: New test.
	* gm2/iso/fail/simpleforward.mod: New test.
	* gm2/iso/fail/simpleforward2.mod: New test.
	* gm2/iso/fail/simpleforward3.mod: New test.
	* gm2/iso/fail/simpleforward4.mod: New test.
	* gm2/iso/fail/simpleforward5.mod: New test.
	* gm2/iso/fail/simpleforward7.mod: New test.
	* gm2/iso/pass/simpleforward.mod: New test.
	* gm2/iso/pass/simpleforward6.mod: New test.

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