Add regression test with typing-full fixture

Author: pareshjoshij

test-data/unit/check-python312.test

@@ -2237,3 +2237,14 @@ class D[*Ts](Generic[Unpack[Us]]):  # E: Generic[...] base class is redundant \
                                     # E: Can only use one type var tuple in a class def
     pass
 [builtins fixtures/tuple.pyi]
+
+[case testPep695GenericTypeAliasReassignment]
+from typing import reveal_type
+
+type A[T] = T | str
+B = A
+reveal_type(B)
+[out]
+main:5: note: Revealed type is "typing.TypeAliasType"
+[builtins fixtures/tuple.pyi]
+[typing fixtures/typing-full.pyi]