MIPS: Fix compile error for unitialized variable in simulator.

src/mips64/simulator-mips64.cc

Index: src/mips64/simulator-mips64.cc
diff --git a/src/mips64/simulator-mips64.cc b/src/mips64/simulator-mips64.cc
index 4b251f2b2fa037cbcbebe72d658bfde9ec66e18e..2025e43bd3ff8a077833bf3387971888907047f1 100644
--- a/src/mips64/simulator-mips64.cc
+++ b/src/mips64/simulator-mips64.cc
@@ -2994,9 +2994,8 @@ void Simulator::DecodeTypeRegisterDRsType(Instruction* instr,
   double ft, fs, fd;
   uint32_t cc, fcsr_cc;
   fs = get_fpu_register_double(fs_reg);
-  if (instr->FunctionFieldRaw() != MOVF) {
-    ft = get_fpu_register_double(ft_reg);
-  }
+  ft = (instr->FunctionFieldRaw() != MOVF) ? get_fpu_register_double(ft_reg)
+                                           : 0.0;
   fd = get_fpu_register_double(fd_reg);
   cc = instr->FCccValue();
   fcsr_cc = get_fcsr_condition_bit(cc);