[stubs] Unify (and optimize) implementation of ToObject.

src/x87/interface-descriptors-x87.cc

Index: src/x87/interface-descriptors-x87.cc
diff --git a/src/x87/interface-descriptors-x87.cc b/src/x87/interface-descriptors-x87.cc
index dacbf1061d29b3f69ce5dc90c197491b60b6d645..91566a7f179b2267a45756ebadf83d1acefac011 100644
--- a/src/x87/interface-descriptors-x87.cc
+++ b/src/x87/interface-descriptors-x87.cc
@@ -103,6 +103,14 @@ void ToNumberDescriptor::InitializePlatformSpecific(
 }
 
 
+void ToObjectDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  // ToObjectStub invokes a function, and therefore needs a context.
+  Register registers[] = {eax};
+  data->InitializePlatformSpecific(arraysize(registers), registers, nullptr);
+}
+
+
 void NumberToStringDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {eax};