[deoptimizer] Preserve double bit patterns correctly.

src/mips64/deoptimizer-mips64.cc

Index: src/mips64/deoptimizer-mips64.cc
diff --git a/src/mips64/deoptimizer-mips64.cc b/src/mips64/deoptimizer-mips64.cc
index ea17124c63ee66503897a8967445de3b45524ccf..8b762bd1179b01fbd58cdc31453f81aebd6dce71 100644
--- a/src/mips64/deoptimizer-mips64.cc
+++ b/src/mips64/deoptimizer-mips64.cc
@@ -93,7 +93,7 @@ void Deoptimizer::SetPlatformCompiledStubRegisters(
 
 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
   for (int i = 0; i < DoubleRegister::kMaxNumRegisters; ++i) {
-    double double_value = input_->GetDoubleRegister(i);
+    Float64 double_value = input_->GetDoubleRegister(i);
     output_frame->SetDoubleRegister(i, double_value);
   }
 }