Graph checker fixups

* Add missing VisitInstrucion in VisitLoadException.
* Add commented VisitInstrucion in VisitConstant. See bug for details.
* For consistency, moved all the VisitInstruction to the beginning of
  the methods.
* Add a check in VisitTryBoundary to check for the HasTryCatch flag.

Bug: 262862764
Test: art/test/testrunner/testrunner.py --host --64 --optimizing -b
Change-Id: I26f06dabea44671f6bce838c60083e1bb0babef4
1 file changed