This was exposed on win64 and manifested as a negative offset during
stack frame collection, i.e. pc < Code::instruction_start() for a
BUILTIN frame.

This happened because StackFrame::LookupCode returns the wrong code
object when call is the last instruction in a code object:
* pc is actually the return address for all but the topmost frame.
* pc points at the next instruction after the call.
* This is beyond the current code object if call is the last
  instruction.
* Lookup itself is naive in that it just returns the first code object
  for which (next_code_obj_addr > pc). It does not check that pc is
  actually within [instruction_start, instruction_end[.
* In this specific case, the pc (== return address) actually pointed
  at the beginning of the header of the next code object.
* We finally calculated offset as (code->instruction_start() - pc),
  but with the wrong code object.

This should be followed up by a proper fix at some point. For instance,
this could be setting pc to (return address - 1) for all but the topmost
frame.

BUG=v8:5311

Review-Url: https://codereview.chromium.org/2284673002
Cr-Commit-Position: refs/heads/master@{#38996}