[FastISel] Make isInTailCallPosition independent of SelectionDAG.

Break out the arguemnts required from SelectionDAG, so that this function can
also be used by FastISel.

llvm-svn: 212844
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 28d8e98..f20c61a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5490,7 +5490,7 @@
 
   // Check if target-independent constraints permit a tail call here.
   // Target-dependent constraints are checked within TLI->LowerCallTo.
-  if (isTailCall && !isInTailCallPosition(CS, DAG))
+  if (isTailCall && !isInTailCallPosition(CS, DAG.getTarget(), *TLI))
     isTailCall = false;
 
   TargetLowering::CallLoweringInfo CLI(DAG);