PR modula2/116048 ICE when encountering wrong kind of qualident

PR modula2/116048 ICE when encountering wrong kind of qualident

Following on from PR-115957 further ICEs can be generated by using the
wrong kind of qualident symbol.  For example using a variable instead of
a type or using a type instead of a const.  This fix tracks the expected
qualident kind state when parsing const, type and variable declarations.
If the error is unrecoverable then a detailed message explaining the
context of the qualident (and why the seen qualident is wrong) is
generated.

gcc/m2/ChangeLog:

	PR modula2/116048
	* Make-lang.in (GM2-COMP-BOOT-DEFS): Add M2StateCheck.def.
	(GM2-COMP-BOOT-MODS): Add M2StateCheck.mod.
	(GM2-COMP-DEFS): Add M2StateCheck.def.
	(GM2-COMP-MODS): Add M2StateCheck.mod.
	* gm2-compiler/M2Quads.mod (StartBuildWith): Generate
	unrecoverable error is the qualident type is NulSym.
	Replace MetaError1 with MetaErrorT1 and position the error
	to the qualident.
	* gm2-compiler/P3Build.bnf (M2StateCheck): Import procedures.
	(seenError): New variable.
	(WasNoError): Remove variable.
	(BlockState): New variable.
	(ErrorString): Rewrite using seenError.
	(CompilationUnit): Ditto.
	(QualidentCheck): New rule.
	(ConstantDeclaration): Bookend with InclConst and ExclConst.
	(Constructor): Add InclConstructor, ExclConstructor and call
	CheckQualident.
	(ConstActualParameters): Call PushState, PopState, InclConstFunc
	and CheckQualident.
	(TypeDeclaration): Bookend with InclType and ExclType.
	(SimpleType): Call QualidentCheck.
	(CaseTag): Ditto.
	(OptReturnType): Ditto.
	(VariableDeclaration): Bookend with InclVar and ExclVar.
	(Designator): Call QualidentCheck.
	(Formal;Type): Ditto.
	* gm2-compiler/PCBuild.bnf (M2StateCheck): Import procedures.
	(ConstantDeclaration): Rewrite using InclConst and ExclConst.
	(Constructor): Bookend with InclConstructor and ExclConstructor.
	Call CheckQualident.
	(ConstructorOrConstActualParameters): Rewrite and cal
	l CheckQualident.
	(ConstActualParameters): Bookend with PushState PopState.
	Call InclConstFunc and CheckQualident.
	* gm2-gcc/init.cc (_M2_M2StateCheck_init): New declaration.
	(_M2_P3Build_init): New declaration.
	(init_PerCompilationInit): Call _M2_M2StateCheck_init and
	_M2_P3Build_init.
	* gm2-compiler/M2StateCheck.def: New file.
	* gm2-compiler/M2StateCheck.mod: New file.

gcc/testsuite/ChangeLog:

	PR modula2/116048
	* gm2/errors/fail/errors-fail.exp: Remove -Wstudents
	and add -Wuninit-variable-checking=all.
	Replace gm2_init_pim with gm2_init_iso.
	* gm2/errors/fail/testfio.mod: Modify test code to
	provoke an error in the first basic block.
	* gm2/errors/fail/testparam.mod: Ditto.
	* gm2/errors/fail/array1.mod: Ditto.
	* gm2/errors/fail/badtype.mod: New test.
	* gm2/errors/fail/badvar.mod: New test.

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