[Gm2] latest cvs changes

[Gaius Mulley]

Hi,

below are the latest changes.  The major bug fix in this set of
patches is to allow non constant constructors for records and
arrays - which was uncovered when writing some test code for
the ISO RealConv module.  RealConv is currently broken - half
way though a re-implementation,

regards,
Gaius


        * new files RealStr.mod, ConvStringReal.def and
          ConvStringReal.mod.
        * gm2/gm2-compiler/M2ALU.def:  IsValueConst (new function).
        * gm2/gm2-compiler/M2ALU.mod:  GetConstructorField return
          symbol rather than Tree.  Add areAllConstants field
          to a constructor value.  IsValueConst (implement new
          function).  ConvertConstToType (new function).
        * gm2/gm2-compiler/M2GCCDeclare.def:  DeclareConstructor
          (new procedure).
        * gm2/gm2-compiler/M2GCCDeclare.mod:  DeclareConstructor
          (implement new procedure).
        * gm2/gm2-compiler/M2GenGCC.def:  DoCopyString exported.
        * gm2/gm2-compiler/M2GenGCC.mod:  call DeclareConstructor
          before it is used.  Also check to see that Composite
          types do not occur in expressions.
        * gm2/gm2-compiler/M2Quads.mod:  modified to allow non
          constant constructors to be used.  General tidying up.
        * gm2/gm2-compiler/M2Range.mod:  call DeclareConstructor
          before possible assignment of constructor.
        * gm2/gm2-compiler/SymbolTable.def:  IsConstructorConstant
          (new procedure).  IsComposite (new procedure).
        * gm2/gm2-compiler/SymbolTable.mod:  IsConst checks to
          see if the constructor is constant.  IsConstructorConstant
          (implement new procedure).  IsComposite (implement new
          procedure).
        * gm2/gm2-libs-iso/RealConv.mod:  reimplemented using
          ConvStringReal.
        * gm2/gm2-compiler/M2ALU.mod:  DefinedByConstants (new
          procedure),  arrayConstants (new procedure),
          fieldsConstant (new procedure) and rangeConstant
          (new procedure).

        * gm2/Make-lang.in:  only copy SYSTEM.def from the
          build directory.  Add ConvStringReal.mod to the list
          of ISO modules.