Make psuedo FEXT_T8I816_ins a custom inserter. It should be expanded
as early as possible; which means during instruction selection.

llvm-svn: 175984
diff --git a/llvm/lib/Target/Mips/MipsISelLowering.h b/llvm/lib/Target/Mips/MipsISelLowering.h
index 2896de5..ac05c83 100644
--- a/llvm/lib/Target/Mips/MipsISelLowering.h
+++ b/llvm/lib/Target/Mips/MipsISelLowering.h
@@ -413,6 +413,9 @@
     MachineBasicBlock *EmitSelT16(unsigned Opc1, unsigned Opc2,
                                   MachineInstr *MI,
                                   MachineBasicBlock *BB) const;
+    MachineBasicBlock *EmitFEXT_T8I816_ins(unsigned BtOpc, unsigned CmpOpc,
+                               MachineInstr *MI,
+                               MachineBasicBlock *BB) const;
   };
 }