X87: [Interpreter] Add support for JS calls.

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 23119d6ea5445aacdaa640d1cb915f7bec45efae..fc5b4be2f7239198fe2d12e06baefac6825261cb 100644
--- a/src/x87/interface-descriptors-x87.cc
+++ b/src/x87/interface-descriptors-x87.cc
@@ -389,6 +389,18 @@ void MathRoundVariantCallFromOptimizedCodeDescriptor::
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
+
+
+void PushArgsAndCallDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  Register registers[] = {
+      eax,  // argument count (including receiver)
+      ebx,  // address of first argument
+      edi   // the target callable to be call
+  };
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
 }  // namespace internal
 }  // namespace v8