[SubZero] Handle relocatable constants for MIPS

src/IceTargetLoweringMIPS32.h

 //===- subzero/src/IceTargetLoweringMIPS32.h - MIPS32 lowering ---*- C++-*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 195 matching lines @@
   }
 
   void _add_s(Variable *Dest, Variable *Src0, Variable *Src1) {
     Context.insert<InstMIPS32Add_s>(Dest, Src0, Src1);
   }
 
   void _addiu(Variable *Dest, Variable *Src, uint32_t Imm) {
     Context.insert<InstMIPS32Addiu>(Dest, Src, Imm);
   }
 
+  void _addiu(Variable *Dest, Variable *Src0, Operand *Src1, RelocOp Reloc) {
+    Context.insert<InstMIPS32Addiu>(Dest, Src0, Src1, Reloc);
+  }
+
   void _c_eq_d(Variable *Src0, Variable *Src1) {
     Context.insert<InstMIPS32C_eq_d>(Src0, Src1);
   }
 
   void _c_eq_s(Variable *Src0, Variable *Src1) {
     Context.insert<InstMIPS32C_eq_s>(Src0, Src1);
   }
 
   void _c_ole_d(Variable *Src0, Variable *Src1) {
     Context.insert<InstMIPS32C_ole_d>(Src0, Src1);
@@ skipping 642 matching lines @@
   explicit TargetHeaderMIPS32(GlobalContext *Ctx);
 
 private:
   ~TargetHeaderMIPS32() = default;
 };
 
 } // end of namespace MIPS32
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGMIPS32_H