Remove unused parameter warning via introducing attribute unused.

Remove unused parameter warning via introducing attribute unused.

Introduce attribute unused into the grammar of gm2 and mc.
Emit attribute ((unused)) during parameters if specified.
Removes many unused warnings when building gm2 under bootstrap
(specifically used during generic walk procedures in M2GCCDeclare.mod).

gcc/m2/ChangeLog:

	* gm2-compiler/M2AsmUtil.mod (UnderScoreString): Removed.
	* gm2-compiler/M2GCCDeclare.mod (DeclareStringConstant): delete
	variable location and remove passing it to any procedure.
	(PromoteToString) remove variable location and remove it from all
	usage.
	(TryDeclareConst) remove tokenno.
	(DeclareConst): remove tokenno.
	* gm2-compiler/M2GenGCC.mod (CodeStatement): Remove first
	parameter for CodeInitStart and CodeFinallyStart.
	(BuildTreeFromInterface): Remove location variable as
	BuildStringConstant no longer has this parameter.
	(CodeInitStart): Remove the unused first parameter.
	(CodeFinallyStart): Remove the unused first parameter.
	(CodeAddr): Remove location variable as
	BuildStringConstant no longer has this parameter.
	* gm2-compiler/M2LexBuf.mod (stop): Removed.
	* gm2-compiler/M2Options.def (m2linemap): Import list replaced
	identifier GetSaveTempsDir.
	* gm2-compiler/M2Options.mod (DynamicStrings): Import list replaced
	identifiers GenModuleListFlag and SaveTempsDir.
	(SetSaveTempsDir) copy directory string.
	(GetSaveTempsDir) New procedure function.
	* gm2-compiler/M2Range.mod (BuildStringParamLoc): Remove location
	variable as it is no longer needed by BuildStringConstant.
	* gm2-compiler/P0SyntaxCheck.bnf: Extend grammar to allow
	attribute unused in parameters.
	* gm2-compiler/P1Build.bnf: Extend grammar to allow
	attribute unused in parameters.
	* gm2-compiler/P2Build.bnf (NameKey): Imported.  (MetaErrorT1)
	Imported.  Extend grammar to allow attribute unused in parameters
	and also check attribute contents for usused and noreturn.
	* gm2-compiler/P3Build.bnf: Extend grammar to allow attribute
	unused in parameters.
	* gm2-compiler/PCBuild.bnf: Extend grammar to allow attribute
	unused in parameters.
	* gm2-compiler/PHBuild.bnf: Extend grammar to allow attribute
	unused in parameters.
	* gm2-compiler/SymbolTable.mod (GetOuterModule): Remove function
	procedure.
	* gm2-gcc/m2decl.cc (BuildStringConstant): Remove unused
	location parameter.
	* gm2-gcc/m2decl.def (BuildStringConstant): Remove unused
	location parameter.
	* gm2-gcc/m2decl.h (BuildStringConstant): Remove unused
	location parameter.
	* m2/gm2-lang.cc: Tidy up comments.
	* m2/m2-tree.def: Tidy up comments.
	* m2/m2-tree.h: Tidy up comments.
	* m2/m2pp.cc: Tidy up comments.
	* m2/m2pp.h: Tidy up comments.
	* mc-boot/GASCII.c: Rebuilt.
	* mc-boot/GArgs.c: Rebuilt.
	* mc-boot/GAssertion.c: Rebuilt.
	* mc-boot/GBreak.c: Rebuilt.
	* mc-boot/GCmdArgs.c: Rebuilt.
	* mc-boot/GDebug.c: Rebuilt.
	* mc-boot/GDynamicStrings.c: Rebuilt.
	* mc-boot/GEnvironment.c: Rebuilt.
	* mc-boot/GFIO.c: Rebuilt.
	* mc-boot/GFormatStrings.c: Rebuilt.
	* mc-boot/GFpuIO.c: Rebuilt.
	* mc-boot/GIO.c: Rebuilt.
	* mc-boot/GIndexing.c: Rebuilt.
	* mc-boot/GM2Dependent.c: Rebuilt.
	* mc-boot/GM2EXCEPTION.c: Rebuilt.
	* mc-boot/GM2RTS.c: Rebuilt.
	* mc-boot/GMemUtils.c: Rebuilt.
	* mc-boot/GNumberIO.c: Rebuilt.
	* mc-boot/GPushBackInput.c: Rebuilt.
	* mc-boot/GRTExceptions.c: Rebuilt.
	* mc-boot/GRTint.c: Rebuilt.
	* mc-boot/GSArgs.c: Rebuilt.
	* mc-boot/GSFIO.c: Rebuilt.
	* mc-boot/GStdIO.c: Rebuilt.
	* mc-boot/GStorage.c: Rebuilt.
	* mc-boot/GStrCase.c: Rebuilt.
	* mc-boot/GStrIO.c: Rebuilt.
	* mc-boot/GStrLib.c: Rebuilt.
	* mc-boot/GStringConvert.c: Rebuilt.
	* mc-boot/GSysStorage.c: Rebuilt.
	* mc-boot/GTimeString.c: Rebuilt.
	* mc-boot/Galists.c: Rebuilt.
	* mc-boot/Gdecl.h: Rebuilt.
	* mc-boot/Gkeyc.c: Rebuilt.
	* mc-boot/Glists.c: Rebuilt.
	* mc-boot/GmcComment.c: Rebuilt.
	* mc-boot/GmcComp.c: Rebuilt.
	* mc-boot/GmcDebug.c: Rebuilt.
	* mc-boot/GmcError.c: Rebuilt.
	* mc-boot/GmcFileName.c: Rebuilt.
	* mc-boot/GmcLexBuf.c: Rebuilt.
	* mc-boot/GmcMetaError.c: Rebuilt.
	* mc-boot/GmcPreprocess.c: Rebuilt.
	* mc-boot/GmcPretty.c: Rebuilt.
	* mc-boot/GmcPrintf.c: Rebuilt.
	* mc-boot/GmcQuiet.c: Rebuilt.
	* mc-boot/GmcReserved.c: Rebuilt.
	* mc-boot/GmcSearch.c: Rebuilt.
	* mc-boot/GmcStack.c: Rebuilt.
	* mc-boot/GmcStream.c: Rebuilt.
	* mc-boot/Gmcp1.c: Rebuilt.
	* mc-boot/Gmcp2.c: Rebuilt.
	* mc-boot/Gmcp3.c: Rebuilt.
	* mc-boot/Gmcp4.c: Rebuilt.
	* mc-boot/Gmcp5.c: Rebuilt.
	* mc-boot/GnameKey.c: Rebuilt.
	* mc-boot/GsymbolKey.c: Rebuilt.
	* mc-boot/Gtop.c: Rebuilt.
	* mc-boot/Gvarargs.c: Rebuilt.
	* mc-boot/Gwlists.c: Rebuilt.
	* mc/decl.def (makeVarParameter): Add parameter to signify used.
	(makeNonVarParameter): Add parameter to signify used.
	(addVarParameters): Add parameter to signify used.
	* mc/decl.mod: Add isused boolean to parameters.
	* mc/mcp1.bnf: Extend grammar to handle attribute unused during
	parameters.
	* mc/mcp2.bnf: Extend grammar to handle attribute unused during
	parameters.
	* mc/mcp3.bnf: Extend grammar to handle attribute unused during
	parameters. (mcPrintf): Import list replaced identifiers makekey
	and makeKey.
	* mc/mcp4.bnf: Extend grammar to handle attribute unused during
	parameters.
	* mc/mcp5.bnf: Extend grammar to handle attribute unused during
	parameters.
	* tools-src/mklink.c: Pass envp with argc, argv parameters for
	module initializer/finalization calls.

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