Fixed HUnaryMathOperation regarding its possible operations.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 9ce7498a32f564c990bc48f986061c0b5dc77233..9c8d9d881d555f18f90c997406327160d2ba8968 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -1310,20 +1310,18 @@ const char* HUnaryMathOperation::OpName() const {
   switch (op()) {
     case kMathFloor: return "floor";
     case kMathRound: return "round";
-    case kMathCeil: return "ceil";
     case kMathAbs: return "abs";
     case kMathLog: return "log";
     case kMathSin: return "sin";
     case kMathCos: return "cos";
     case kMathTan: return "tan";
-    case kMathASin: return "asin";
-    case kMathACos: return "acos";
-    case kMathATan: return "atan";
     case kMathExp: return "exp";
     case kMathSqrt: return "sqrt";
-    default: break;
+    case kMathPowHalf: return "pow-half";
+    default:
+      UNREACHABLE();
+      return NULL;
   }
-  return "(unknown operation)";
 }