X87: [Interpreter] Add support for JS calls.

src/x87/interface-descriptors-x87.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X87
 
 #include "src/interface-descriptors.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 371 matching lines @@
 
 void MathRoundVariantCallFromOptimizedCodeDescriptor::
     InitializePlatformSpecific(CallInterfaceDescriptorData* data) {
   Register registers[] = {
       edi,  // math rounding function
       edx,  // vector slot id
       ebx   // type vector
   };
   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
 
 #endif  // V8_TARGET_ARCH_X87