[DynInst_API:] [dyninst/dyninst] a8c557: Set register space in RelDataPatch

[Sunny Shah <shah28@xxxxxxxx>]

  Branch: refs/heads/arm64/feature/relocation
  Home:   https://github.com/dyninst/dyninst
  Commit: a8c557853082185bb8c9b97e2c70b7e0c8071927
      https://github.com/dyninst/dyninst/commit/a8c557853082185bb8c9b97e2c70b7e0c8071927
  Author: Sunny Shah <shah28@xxxxxxxx>
  Date:   2017-04-24 (Mon, 24 Apr 2017)

  Changed paths:
    M dataflowAPI/src/ABI.C
    M dyninstAPI/src/Relocation/Widgets/RelDataWidget.C
    M dyninstAPI/src/Relocation/Widgets/RelDataWidget.h

  Log Message:
  -----------
  Set register space in RelDataPatch

The register space for the codeGen object used in RelDataPatch needs to be set before it is passed to insnCodeGen, since the latter uses it when getting a scratch register.

If the codeGen point in RelDataPatch is null, a new point needs to be generated referencing the previous instruction. This requires pointers to the function and block instances. To store these pointe
ers from RelDataWidget, two new fields (and their setters) are added to RelDataPatch.