[SubZero] Handle relocatable constants for MIPS

src/IceTargetLoweringMIPS32.h

Index: src/IceTargetLoweringMIPS32.h
diff --git a/src/IceTargetLoweringMIPS32.h b/src/IceTargetLoweringMIPS32.h
index 842f266e2be730aced312e48437e56d3910393bb..f7fcbb13651f500d70f8551693a874189960e41d 100644
--- a/src/IceTargetLoweringMIPS32.h
+++ b/src/IceTargetLoweringMIPS32.h
@@ -213,6 +213,10 @@ public:
     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);
   }