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

src/ppc/builtins-ppc.cc

Index: src/ppc/builtins-ppc.cc
diff --git a/src/ppc/builtins-ppc.cc b/src/ppc/builtins-ppc.cc
index 3c83c942bbfb8bd789eef918b1594ec1c9f49813..a2dcbf3531c22f359246fa59b37da88d734531bf 100644
--- a/src/ppc/builtins-ppc.cc
+++ b/src/ppc/builtins-ppc.cc
@@ -866,10 +866,8 @@ void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
 //   o sp: stack pointer
 //   o lr: return address
 //
-// The function builds a JS frame.  Please see JavaScriptFrameConstants in
-// frames-ppc.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
@@ -966,7 +964,9 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // and header removal.
   __ addi(ip, ip, Operand(Code::kHeaderSize - kHeapObjectTag));
   __ Call(ip);
-  __ bkpt(0);  // Does not return here.
+
+  // Even though the first bytecode handler was called, we will never return.
+  __ Abort(kUnexpectedReturnFromBytecodeHandler);
 }