[pypy-issue] Issue #1894: KeyError (core dumped) on unicode triple quoted double quote literal (pypy/pypy)

[Anthony Sottile]

New issue 1894: KeyError (core dumped) on unicode triple quoted double quote literal
https://bitbucket.org/pypy/pypy/issue/1894/keyerror-core-dumped-on-unicode-triple

Anthony Sottile:

```
$ pypy3 -m compileall test.py
Compiling 'test.py'...
RPython traceback:
  File "pypy_goal_targetpypystandalone.c", line 2059, in entry_point
  File "pypy_interpreter_pyframe.c", line 3779, in PyFrame_execute_frame
  File "rpython_jit_metainterp_warmspot.c", line 1487, in ll_portal_runner__Unsigned_Bool_pypy_interpreter
  File "pypy_module_pypyjit_interp_jit.c", line 289, in portal_4
  File "pypy_interpreter_pyopcode.c", line 6902, in handle_bytecode__AccessDirect_None
  File "pypy_interpreter_pyopcode.c", line 9984, in dispatch_bytecode__AccessDirect_None
  File "pypy_interpreter_pyopcode.c", line 17466, in call_function__AccessDirect_None
  File "pypy_interpreter_pyframe.c", line 3779, in PyFrame_execute_frame
  File "rpython_jit_metainterp_warmspot.c", line 1487, in ll_portal_runner__Unsigned_Bool_pypy_interpreter
  File "pypy_module_pypyjit_interp_jit.c", line 289, in portal_4
  File "pypy_interpreter_pyopcode.c", line 6902, in handle_bytecode__AccessDirect_None
  ...
Fatal RPython error: KeyError
Aborted (core dumped)
$ cat test.py
u""""""
$ pypy3 --version
Python 3.2.5 (986752d005bb, Jun 19 2014, 16:18:53)
[PyPy 2.3.1 with GCC 4.6.3]
```

Interestingly the following files are fine:
```
u''''''
```

```
u""
```

```
u''
```