Add generic test

Author: saulshanabrook

test-data/unit/check-typeguard.test

@@ -754,6 +754,19 @@ if E()(x):
     reveal_type(x)  # N: Revealed type is "builtins.int"
 [builtins fixtures/tuple.pyi]
 
+[case testNoCrashOnDunderCallTypeIsTemporaryObjectGeneric]
+from typing import Generic, TypeVar
+from typing_extensions import TypeIs
+T = TypeVar("T")
+class E(Generic[T]):
+    def __init__(self) -> None: ...
+    def __call__(self, o: object) -> TypeIs[T]:
+        return True
+x = object()
+if E[int]()(x):
+    reveal_type(x)  # N: Revealed type is "builtins.int"
+[builtins fixtures/tuple.pyi]
+
 [case testTypeGuardRestrictAwaySingleInvariant]
 from typing import List
 from typing_extensions import TypeGuard