MIPS: Implement Math.tan in generated code.

src/mips/lithium-codegen-mips.h

Index: src/mips/lithium-codegen-mips.h
diff --git a/src/mips/lithium-codegen-mips.h b/src/mips/lithium-codegen-mips.h
index ad11e3a5c6aea88682a0ef85700f7f5152ae82a8..c67b46be7e0eccedc4474d5a05f748c341a6564c 100644
--- a/src/mips/lithium-codegen-mips.h
+++ b/src/mips/lithium-codegen-mips.h
@@ -242,6 +242,7 @@ class LCodeGen BASE_EMBEDDED {
   void DoMathSqrt(LUnaryMathOperation* instr);
   void DoMathPowHalf(LUnaryMathOperation* instr);
   void DoMathLog(LUnaryMathOperation* instr);
+  void DoMathTan(LUnaryMathOperation* instr);
   void DoMathCos(LUnaryMathOperation* instr);
   void DoMathSin(LUnaryMathOperation* instr);