[Interpreter] Add CallRuntime support to the interpreter.

src/x64/interface-descriptors-x64.cc

Index: src/x64/interface-descriptors-x64.cc
diff --git a/src/x64/interface-descriptors-x64.cc b/src/x64/interface-descriptors-x64.cc
index a062df590fd83cd28892e908c108260009f9403c..c654c94f1fe2f35fbb0b8513bbbc86d31652f5fa 100644
--- a/src/x64/interface-descriptors-x64.cc
+++ b/src/x64/interface-descriptors-x64.cc
@@ -392,16 +392,27 @@ void MathRoundVariantCallFromOptimizedCodeDescriptor::
 }
 
 
-void PushArgsAndCallDescriptor::InitializePlatformSpecific(
+void InterpreterPushArgsAndCallDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
-      rax,  // argument count (including receiver)
+      rax,  // argument count (not including receiver)
       rbx,  // address of first argument
       rdi   // the target callable to be call
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
+
+void InterpreterCEntryDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  Register registers[] = {
+      rax,  // argument count (argc)
+      r15,  // address of first argument (argv)
+      rbx   // the runtime function to call
+  };
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
 }  // namespace internal
 }  // namespace v8