Revert r10908 due to flakiness and crashes.

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index 1c4e1da3fbca3d189ba7d8f14fa2fab4b361dae6..ae07c1e45601bcf55bffedeefe8678f5f16cd5d3 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1169,7 +1169,7 @@ LInstruction* LChunkBuilder::DoInvokeFunction(HInvokeFunction* instr) {
 
 LInstruction* LChunkBuilder::DoUnaryMathOperation(HUnaryMathOperation* instr) {
   BuiltinFunctionId op = instr->op();
-  if (op == kMathLog || op == kMathSin || op == kMathCos || op == kMathTan) {
+  if (op == kMathLog || op == kMathSin || op == kMathCos) {
     LOperand* input = UseFixedDouble(instr->value(), f4);
     LUnaryMathOperation* result = new(zone()) LUnaryMathOperation(input, NULL);
     return MarkAsCall(DefineFixedDouble(result, f4), instr);