Subzero: Fix a build error against LLVM trunk.

src/IceTargetLoweringMIPS32.cpp

 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 /// \brief Implements the TargetLoweringMIPS32 class, which consists almost
@@ skipping 978 matching lines @@
   InstList::reverse_iterator RI, E;
   for (RI = Insts.rbegin(), E = Insts.rend(); RI != E; ++RI) {
     if (llvm::isa<InstMIPS32Ret>(*RI))
       break;
   }
   if (RI == E)
     return;
 
   // Convert the reverse_iterator position into its corresponding (forward)
   // iterator position.
-  InstList::iterator InsertPoint = RI.base();
+  InstList::iterator InsertPoint = reverseToForwardIterator(RI);
   --InsertPoint;
   Context.init(Node);
   Context.setInsertPoint(InsertPoint);
 
   Variable *SP = getPhysicalRegister(RegMIPS32::Reg_SP);
   if (UsesFramePointer) {
     Variable *FP = getPhysicalRegister(RegMIPS32::Reg_FP);
     // For late-stage liveness analysis (e.g. asm-verbose mode), adding a fake
     // use of SP before the assignment of SP=FP keeps previous SP adjustments
     // from being dead-code eliminated.
@@ skipping 1595 matching lines @@
   Str << "\t.set\t"
       << "nomips16\n";
 }
 
 SmallBitVector TargetMIPS32::TypeToRegisterSet[RCMIPS32_NUM];
 SmallBitVector TargetMIPS32::TypeToRegisterSetUnfiltered[RCMIPS32_NUM];
 SmallBitVector TargetMIPS32::RegisterAliases[RegMIPS32::Reg_NUM];
 
 } // end of namespace MIPS32
 } // end of namespace Ice