Error on unicode surrogates in mypyc

[ilevkivskyi]

This PR is expected to fail until mypyc/ast_serialize#82 is merged and released.

cc @JukkaL

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

packaging (https://github.com/pypa/packaging)
+ src/packaging/__init__.py: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
+ https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
+ Please report a bug at https://github.com/python/mypy/issues
+ version: 2.4.0+dev.4afbdec6456574fcc4f3ec75245d870c9f8dfcf3
+ src/packaging/__init__.py: note: use --pdb to drop into pdb
+ Traceback (most recent call last):
+   File "", line 6, in <module>
+     sys.exit(console_entry())
+   File "/__main__.py", line 16, in console_entry
+     main()
+   File "/main.py", line 154, in main
+     res, messages, blockers = run_build(sources, options, fscache, t0, stdout, stderr)
+   File "/main.py", line 244, in run_build
+     res = build.build(sources, options, None, flush_errors, fscache, stdout, stderr)
+   File "/build.py", line 422, in build
+     result = build_inner(
+   File "/build.py", line 537, in build_inner
+     graph = dispatch(sources, manager, stdout, connect_threads)
+   File "/build.py", line 4078, in dispatch
+     graph = load_graph(sources, manager)
+   File "/build.py", line 4311, in load_graph
+     manager.parse_all([state for state in new if state.needs_parse])
+   File "/build.py", line 1054, in parse_all
+     with state.wrap_context():
+   File "/opt/hostedtoolcache/Python/3.14.7/x64/lib/python3.14/contextlib.py", line 162, in __exit__
+     self.gen.throw(value)
+   File "/build.py", line 3075, in wrap_context
+     yield
+   File "/build.py", line 1063, in parse_all
+     state.tree = load_from_raw(
+                  ~~~~~~~~~~~~~^
+         state.xpath,
+         ^^^^^^^^^^^^
+     ...<4 lines>...
+         imports_only=bool(self.workers),
+         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+     )
+     ^
+   File "/parse.py", line 80, in load_from_raw
+     defs = read_statements(state, data, n)
+   File "/nativeparse.py", line 269, in read_statements
+     stmt = read_statement(state, data)
+   File "/nativeparse.py", line 318, in read_statement
+     rvalue = read_expression(state, data)
+   File "/nativeparse.py", line 1351, in read_expression
+     se.has_surrogates = read_bool(data)
+                         ~~~~~~~~~^^^^^^
+ ValueError: invalid bool value
+ 

nox (https://github.com/wntrblm/nox)
- nox/virtualenv.py:52: error: Cannot find implementation or library stub for module named "python_discovery"  [import-not-found]
- nox/virtualenv.py:147: error: Cannot find implementation or library stub for module named "platformdirs"  [import-not-found]
- nox/virtualenv.py:367: error: Cannot find implementation or library stub for module named "pbs_installer"  [import-not-found]
- nox/_cli.py:195: error: Cannot find implementation or library stub for module named "python_discovery"  [import-not-found]
- nox/_cli.py:195: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
+ nox/__init__.py: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
+ https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
+ Please report a bug at https://github.com/python/mypy/issues
+ version: 2.4.0+dev.4afbdec6456574fcc4f3ec75245d870c9f8dfcf3
+ nox/__init__.py: note: use --pdb to drop into pdb
+ Traceback (most recent call last):
+   File "", line 6, in <module>
+     sys.exit(console_entry())
+   File "/__main__.py", line 16, in console_entry
+     main()
+   File "/main.py", line 154, in main
+     res, messages, blockers = run_build(sources, options, fscache, t0, stdout, stderr)
+   File "/main.py", line 244, in run_build
+     res = build.build(sources, options, None, flush_errors, fscache, stdout, stderr)
+   File "/build.py", line 422, in build
+     result = build_inner(
+   File "/build.py", line 537, in build_inner
+     graph = dispatch(sources, manager, stdout, connect_threads)
+   File "/build.py", line 4078, in dispatch
+     graph = load_graph(sources, manager)
+   File "/build.py", line 4311, in load_graph
+     manager.parse_all([state for state in new if state.needs_parse])
+   File "/build.py", line 1054, in parse_all
+     with state.wrap_context():
+   File "/opt/hostedtoolcache/Python/3.14.7/x64/lib/python3.14/contextlib.py", line 162, in __exit__
+     self.gen.throw(value)
+   File "/build.py", line 3075, in wrap_context
+     yield
+   File "/build.py", line 1063, in parse_all
+     state.tree = load_from_raw(
+                  ~~~~~~~~~~~~~^
+         state.xpath,
+         ^^^^^^^^^^^^
+     ...<4 lines>...
+         imports_only=bool(self.workers),
+         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+     )
+     ^
+   File "/parse.py", line 80, in load_from_raw
+     defs = read_statements(state, data, n)
+   File "/nativeparse.py", line 269, in read_statements
+     stmt = read_statement(state, data)
+   File "/nativeparse.py", line 318, in read_statement
+     rvalue = read_expression(state, data)
+   File "/nativeparse.py", line 1506, in read_expression
+     items = read_expression_list(state, data)
+   File "/nativeparse.py", line 1761, in read_expression_list
+     return [read_expression(state, data) for i in range(n)]
+             ~~~~~~~~~~~~~~~^^^^^^^^^^^^^
+   File "/nativeparse.py", line 1351, in read_expression
+     se.has_surrogates = read_bool(data)
+                         ~~~~~~~~~^^^^^^
+ ValueError: invalid bool value
+