[InstrInfo] Refactor foldOperandImpl to thread through InsertPt. NFC

Summary:
This was a longstanding FIXME and is a necessary precursor to cases
where foldOperandImpl may have to create more than one instruction
(e.g. to constrain a register class). This is the split out NFC changes from
D6262.

Reviewers: pete, ributzka, uweigand, mcrosier

Reviewed By: mcrosier

Subscribers: mcrosier, ted, llvm-commits

Differential Revision: http://reviews.llvm.org/D10174

llvm-svn: 239336
diff --git a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
index 49b4517..e566a97 100644
--- a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
@@ -779,10 +779,9 @@
   return false;
 }
 
-MachineInstr *HexagonInstrInfo::foldMemoryOperandImpl(MachineFunction &MF,
-                                                      MachineInstr *MI,
-                                                      ArrayRef<unsigned> Ops,
-                                                      int FI) const {
+MachineInstr *HexagonInstrInfo::foldMemoryOperandImpl(
+    MachineFunction &MF, MachineInstr *MI, ArrayRef<unsigned> Ops,
+    MachineBasicBlock::iterator InsertPt, int FI) const {
   // Hexagon_TODO: Implement.
   return nullptr;
 }