Fix PR11985

- BlockAddress has no support of BA + offset form and there is no way to
  propagate that offset into machine operand;
- Add BA + offset support and a new interface 'getTargetBlockAddress' to
  simplify target block address forming;
- All targets are modified to use new interface and X86 backend is enhanced to
  support BA + offset addressing.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163743 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86ISelLowering.cpp

@@ -7368,9 +7368,10 @@ X86TargetLowering::LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const {
     Subtarget->ClassifyBlockAddressReference();
   CodeModel::Model M = getTargetMachine().getCodeModel();
   const BlockAddress *BA = cast<BlockAddressSDNode>(Op)->getBlockAddress();
+  int64_t Offset = cast<BlockAddressSDNode>(Op)->getOffset();
   DebugLoc dl = Op.getDebugLoc();
-  SDValue Result = DAG.getBlockAddress(BA, getPointerTy(),
-                                       /*isTarget=*/true, OpFlags);
+  SDValue Result = DAG.getTargetBlockAddress(BA, getPointerTy(), Offset,
+                                             OpFlags);
 
   if (Subtarget->isPICStyleRIPRel() &&
       (M == CodeModel::Small || M == CodeModel::Kernel))