Bugfixes for default scope, tidying up of code and neater error messages.

Bugfixes for default scope, tidying up of code and neater error messages.

gcc/m2/ChangeLog:

	* m2/Make-lang.in (m2/gm2-compiler-boot/M2Error.o): New rule
	to build M2Error.o using the --entended-opaque option since
	M2Error.mod aggressively uses opaque data types.
	* bnf/m2-1.bnf (DefProcedureHeading) ensure DefaultProcedure
	scope is created before any further tokens are consumed.
	Call LeaveErrorScope at the end of the rule.
	* bnf/m2-2.bnf (DefProcedureHeading): Call LeaveErrorScope
	at the end of the rule.
	* bnf/m2-3.bnf (DefProcedureHeading): Call LeaveErrorScope
	at the end of the rule.
	* bnf/m2-c.bnf (DefProcedureHeading): Call LeaveErrorScope
	at the end of the rule.
	* bnf/m2-h.bnf (DefProcedureHeading): Call DefaultProcedure
	and the beginning and LeaveErrorScope at the end of the rule.
	* bnf/m2.bnf (DefProcedureHeading): Call DefaultProcedure
	and the beginning of the rule.
	* gm2-compiler/M2Comp.mod (M2Error): Import list replaced
	identifiers ParsingComplete; and ResetErrorScope;.
	* gm2-compiler/M2Error.def (NameKey): Renamed ParsingComplete to
	ResetErrorScope.  Call ResetErrorScope before each pass commenses.
	Import list replaced identifiers LeaveScope,
	ParsingComplete by EnterErrorScope, ErrorScope,
	GetCurrentErrorScope,
	(LeaveErrorScope): New procedure.  (ResetErrorScope): New
	procedure.  (LeaveScope) Removed.
	* gm2-compiler/M2Error.mod (M2Options): Import StackOfAddress.
	(printf2) Imported. (printf3) Imported.
	(IsErrorScopeNul): New procedure function.
	(GetAnnounceScope): Re-implementation.
	(IsSameScope): New procedure function.
	(AnnounceScope): Detect no scope.
	(newErrorScope): Use scopeArray to push a new scope.
	(DefaultProgramModule):  New implementation.
	(DefaultImplementationModule): New implementation.
	(DefaultDefinitionModule): New implementation.
	(DefaultInnerModule): New implementation.
	(GetCurrentErrorScope): New procedure function.
	* gm2-compiler/M2MetaError.def: Extend the specifiers to
	allow error contents to be pushed to a string stack;
	string stack contents to be popped onto the output string;
	replace dictionary string by the current output string and
	remove all contents in the dictionary.
	* gm2-compiler/M2MetaError.mod (addEntry) New procedure.
	(killEntry) New procedure function.
	(lookupDefine) New procedure function.
	(lookupString) New procedure function.
	(newEntry) New procedure function.
	(popOutput) New procedure function.
	(processDefine) New procedure.
	(pushOutput) New procedure function.
	(readWord) New procedure function.
	(resetDictionary) New procedure.
	(doErrorScopeMod) Enter error scope before
	generate an error.
	(doErrorScopeDef) Enter error scope before
	generate an error.
	(op): Handle 'Q', 'X', 'Y', 'Z' format directives.
	* gm2-compiler/M2Scope.mod (SymbolTable): Import list includes
	identifier GetErrorScope.
	(enter): Re-implemented.
	* gm2-compiler/M2StackWord.mod: Renamed data types so
	they are easier to debug during bootstrap (avoid name clashes
	with the M2StackAddress module).
	* gm2-compiler/P0SymBuild.mod (EndProcedure): Call
	LeaseErrorScope instead of LeaveScope at the end of the procedure.
	* gm2-compiler/P2SymBuild.mod (P2EndBuildDefModule): Call
	LeaseErrorScope instead of LeaveScope at the end of the procedure.
	(P2EndBuildImplementationModule): Call
	LeaseErrorScope instead of LeaveScope at the end of the procedure.
	(P2EndBuildProgramModule): Call
	LeaseErrorScope instead of LeaveScope at the end of the procedure.
	(EndBuildInnerModule): Call
	LeaseErrorScope instead of LeaveScope at the end of the procedure.
	(P3EndBuildImpModule): Call
	LeaseErrorScope instead of LeaveScope at the end of the procedure.
	(P3EndBuildProgModule): Call
	LeaseErrorScope instead of LeaveScope at the end of the procedure.
	(EndBuildInnerModule): Call
	LeaseErrorScope instead of LeaveScope at the end of the procedure.
	* gm2-compiler/PCSymBuild.mod (PCEndBuildDefModule): Call
	LeaseErrorScope instead of
	LeaveScope at the end of the procedure.
	(PCEndBuildImpModule): Call LeaseErrorScope instead of
	LeaveScope at the end of the procedure.
	(PCEndBuildProgModule): Call LeaseErrorScope instead of
	LeaveScope at the end of the procedure.
	(PCEndBuildInnerModule): Call LeaseErrorScope instead of
	LeaveScope at the end of the procedure.
	* gm2-compiler/SymbolKey.def (NoOfNodes): New procedure
	function.
	(ForeachNodeConditionDo) New procedure.
	* gm2-compiler/SymbolKey.mod (NoOfNodes): New procedure
	function.
	(ContainsSymKey): Call FindNodeParentInTree instead of
	FindNodeAndParentInTree.
	(GetSymKey): Call FindNodeParentInTree instead of
	FindNodeAndParentInTree.
	(DelSymKey): Call FindNodeParentInTree instead of
	FindNodeAndParentInTree.
	(FindNodeParentInTree): Renamed from FindNodeAndParentInTree.
	(IsEmptyTree): Reformatted.  (DoesTreeContainAny): Reformatted.
	(SearchForAny): Reformatted.  (ForeachNodeConditionDo) New
	procedure.  (SearchConditional) New procedure.
	* gm2-compiler/SymbolTable.def (GetErrorScope): New procedure
	function.  (PutErrorScope) New procedure.
	* gm2-compiler/SymbolTable.def (GetErrorScope): New procedure
	function implemented.  (PutErrorScope) New procedure implemented.
	(AddListify) New procedure.  (Listify) New procedure.
	(errorScope) field added to procedure, module, defimp
	symbols and initialized	during their construction.

Signed-off-by: Gaius Mulley <gaius.mulley@southwales.ac.uk>