ClassCastExceptions triggered as part of syntax errors

[fniephaus]

Repro

$ graalpython
Python 3.8.2 (Fri May 15 05:42:24 PDT 2020)
[GraalVM CE, Java 11.0.7] on darwin
Type "help", "copyright", "credits" or "license" for more information.
Please note: This Python implementation is in the very early stages, and can run little more than basic benchmarks at this point.
>>> lambda: x:x
  File "<stdin>", line 1
SyntaxError: com.oracle.graal.python.nodes.function.FunctionDefinitionNode cannot be cast to com.oracle.graal.python.nodes.frame.ReadNode

Expected

$ python3
Python 3.7.7 (default, Mar 10 2020, 15:43:33)
[Clang 11.0.0 (clang-1100.0.33.17)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> lambda: x:x
  File "<stdin>", line 1
SyntaxError: illegal target for annotation