This fixes all kinds of problems with array handling. There are still bugs to

be fixed, but we are getting much closer now.

    * Make DSNode::TypeRec a full fledged DSTypeRec type.
    * Add methods used to update and access the typerecords elements
    * Add methods to query if and to cause a node to be completely folded
    * DSGraph construction doesn't use the allocation type for anything at all,
      now nodes get their type information based on how they are used.
    * Fixed a bug with global value handling introduced in the last checkin
    * GEP support is now much better, arrays are handled correctly.  The array
      flag is now updated in type records.  There are still cases that are not
      handled yet (we do not detect pessimizations), but getting much closer.

llvm-svn: 4465