[deoptimizer] Preserve double bit patterns correctly.

src/x87/deoptimizer-x87.cc

Index: src/x87/deoptimizer-x87.cc
diff --git a/src/x87/deoptimizer-x87.cc b/src/x87/deoptimizer-x87.cc
index 20bd4775d1921848859af757f2287195a6adbdef..521b69d7cf16327c1e4b3f07b4401f470184369a 100644
--- a/src/x87/deoptimizer-x87.cc
+++ b/src/x87/deoptimizer-x87.cc
@@ -181,7 +181,7 @@ void Deoptimizer::SetPlatformCompiledStubRegisters(
 
 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
   for (int i = 0; i < X87Register::kMaxNumRegisters; ++i) {
-    double double_value = input_->GetDoubleRegister(i);
+    Float64 double_value = input_->GetDoubleRegister(i);
     output_frame->SetDoubleRegister(i, double_value);
   }
 }