PR modula2/122499: misspelt procedure in import list causes clutter

PR modula2/122499: misspelt procedure in import list causes clutter

A misspelt ident in an import list causes a sequence of clutted errors.
This bug fix filters unknowns built during import lists.  It also
checks for spelling mistakes against the modules exported identifiers.

gcc/m2/ChangeLog:

	PR modula2/122499
	* gm2-compiler/M2StackSpell.mod (PushName): Add comment.
	(GetSpellHint): Rewrite.
	(GetExportedSpellHint): New procedure function.
	(GetScopeSpellHint): New procedure function.
	* gm2-compiler/P1Build.bnf (IdentScope): Rewrite.
	(PossiblyExportIdent): Ditto.
	* gm2-compiler/P1SymBuild.mod (BuildImportInnerModule): Add
	parameter to AddNameToImportList.
	* gm2-compiler/SymbolTable.def (GetUnknownOnImport): New
	procedure function.
	(GetUnknownDeclScope): Ditto.
	(AddNameToScope): Add tok parameter.
	(AddNameToImportList): Ditto.
	* gm2-compiler/SymbolTable.mod (SymUndefined): New field
	declScope.
	New field onImport.
	(MakeObject): Add tok parameter.
	(FillInUnknownFields): Initialize declScope.
	Initialize onImport.
	(GetUnknownOnImport): New procedure function.
	(GetUnknownDeclScope): Ditto.
	(AddNameToScope): Pass tok to MakeObject.
	(AddNameToImportList): Add tok parameter.
	Pass tok to MakeObject.
	(GetDeclaredSym): Add parameters to FillInUnknownFields.
	(RequestSym): Ditto.
	(FetchUnknownFromModule): Ditto.
	(FetchUnknownFromDefImp): Ditto.
	(FetchUnknownFrom): Ditto.

gcc/testsuite/ChangeLog:

	PR modula2/122499
	* gm2.dg/spell/iso/fail/badimport2.mod: New test.
	* gm2.dg/spell/iso/fail/badimport3.mod: New test.
	* gm2.dg/spell/iso/fail/badimport4.mod: New test.

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