Age code to allow reclaiming old unexecuted functions

src/x64/full-codegen-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 120 matching lines @@
     __ int3();
   }
 #endif
 
   // Strict mode functions and builtins need to replace the receiver
   // with undefined when called as functions (without an explicit
   // receiver object). rcx is zero for method calls and non-zero for
   // function calls.
   if (!info->is_classic_mode() || info->is_native()) {
     Label ok;
+    Label begin;
+    __ bind(&begin);
     __ testq(rcx, rcx);
     __ j(zero, &ok, Label::kNear);
     // +1 for return address.
     int receiver_offset = (info->scope()->num_parameters() + 1) * kPointerSize;
     __ LoadRoot(kScratchRegister, Heap::kUndefinedValueRootIndex);
     __ movq(Operand(rsp, receiver_offset), kScratchRegister);
     __ bind(&ok);
+    ASSERT_EQ(kSizeOfFullCodegenStrictModePrologue, ok.pos() - begin.pos());
   }
 
   // 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
   // the frame (that is done below).
   FrameScope frame_scope(masm_, StackFrame::MANUAL);
 
   __ push(rbp);  // Caller's frame pointer.
   __ movq(rbp, rsp);
   __ push(rsi);  // Callee's context.
@@ skipping 4356 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64