[interpreter] Add a safety-net for interpreter entry.

src/x87/builtins-x87.cc

Index: src/x87/builtins-x87.cc
diff --git a/src/x87/builtins-x87.cc b/src/x87/builtins-x87.cc
index 2d73650adc6de3fbf5989340b782a8e20953d0ea..9c3139f32e66c7c676624184dbe0f17a2da9b4aa 100644
--- a/src/x87/builtins-x87.cc
+++ b/src/x87/builtins-x87.cc
@@ -533,10 +533,8 @@ void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
 //   o ebp: the caller's frame pointer
 //   o esp: stack pointer (pointing to return address)
 //
-// The function builds a JS frame.  Please see JavaScriptFrameConstants in
-// frames-ia32.h for its layout.
-// TODO(rmcilroy): We will need to include the current bytecode pointer in the
-// frame.
+// The function builds an interpreter frame.  See InterpreterFrameConstants in
+// frames.h for its layout.
 void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // Open a frame scope to indicate that there is a frame on the stack.  The
   // MANUAL indicates that the scope shouldn't actually generate code to set up
@@ -645,8 +643,9 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // and header removal.
   __ add(ebx, Immediate(Code::kHeaderSize - kHeapObjectTag));
   __ call(ebx);
-  __ nop();  // Ensure that return address still counts as interpreter entry
-             // trampoline.
+
+  // Even though the first bytecode handler was called, we will never return.
+  __ Abort(kUnexpectedReturnFromBytecodeHandler);
 }