[PEI] Pass the frame index operand number to the eliminateFrameIndex function.

Each target implementation was needlessly recomputing the index.
Part of rdar://13076458

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174083 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/PrologEpilogInserter.cpp

@@ -766,7 +766,7 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) {
           // If this instruction has a FrameIndex operand, we need to
           // use that target machine register info object to eliminate
           // it.
-          TRI.eliminateFrameIndex(MI, SPAdj,
+          TRI.eliminateFrameIndex(MI, SPAdj, i,
                                   FrameIndexVirtualScavenging ?  NULL : RS);
 
           // Reset the iterator if we were at the beginning of the BB.