[Beignet] [PATCH 4/5] GBE: enable constant expression processing.

[Song, Ruiling]

+      // Check whether this is a constant drived from a pointer.
+      Constant *itC = c;
+      while(isa<ConstantExpr>(itC))
+        itC = dyn_cast<ConstantExpr>(itC)->getOperand(0);
+      if (itC->getType()->isPointerTy())
+        return getConstantPointerRegister(dyn_cast<ConstantExpr>(c), elemID);
+      //else
+      //  assert(0);
I think the commented code is useless, you can remove it.

     }