[SubZero] Generate ELF output for MIPS

src/IceInstMIPS32.h

Index: src/IceInstMIPS32.h
diff --git a/src/IceInstMIPS32.h b/src/IceInstMIPS32.h
index 5dc836713db774ea7a2f25b74f08b2c6af2a1425..0252e45fd5e9f1020a94fd3c5c55ffd9d8281cc2 100644
--- a/src/IceInstMIPS32.h
+++ b/src/IceInstMIPS32.h
@@ -199,6 +199,8 @@ public:
     Xori
   };
 
+  static constexpr size_t InstSize = sizeof(uint32_t);
+
   static const char *getWidthString(Type Ty);
 
   void dump(const Cfg *Func) const override;
@@ -675,7 +677,7 @@ public:
   }
   bool repointEdges(CfgNode *OldNode, CfgNode *NewNode) override;
   void emit(const Cfg *Func) const override;
-  void emitIAS(const Cfg *Func) const override { (void)Func; };
+  void emitIAS(const Cfg *Func) const override;
   void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Instr) { return isClassof(Instr, Br); }