[mips] Remove incorrect DebugLoc entries from prologue

This has been causing the prologue_end to be incorrectly positioned.

Patch by Vladimir Radosavljevic.

Differential Revision: http://reviews.llvm.org/D11293

llvm-svn: 246309
diff --git a/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp b/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
index cb46d73..dff30c7 100644
--- a/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
+++ b/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
@@ -131,7 +131,7 @@
   MachineBasicBlock::iterator I = MBB.begin();
   MachineRegisterInfo &RegInfo = MF.getRegInfo();
   const TargetInstrInfo &TII = *Subtarget->getInstrInfo();
-  DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
+  DebugLoc DL;
   unsigned V0, V1, GlobalBaseReg = MipsFI->getGlobalBaseReg();
   const TargetRegisterClass *RC;
   const MipsABIInfo &ABI = static_cast<const MipsTargetMachine &>(TM).getABI();