Fix test names

Author: p-sawicki

mypyc/test-data/run-lists.test

@@ -466,7 +466,7 @@ assert not list_in_mixed(object)
 assert list_in_mixed(type)
 
 [case testListBuiltFromGenerator]
-def test() -> None:
+def test_from_gen() -> None:
     source_a = ["a", "b", "c"]
     a = list(x + "f2" for x in source_a)
     assert a == ["af2", "bf2", "cf2"]
@@ -486,12 +486,6 @@ def test() -> None:
     f = list("str:" + x for x in source_str)
     assert f == ["str:a", "str:b", "str:c", "str:d"]
 
-[case testNextBug]
-from typing import List, Optional
-
-def test(x: List[int]) -> None:
-    res = next((i for i in x), None)
-
 [case testListGetItemWithBorrow]
 from typing import List
 
@@ -540,7 +534,7 @@ def test_sorted() -> None:
 
 [case testIsInstance]
 from copysubclass import subc
-def test() -> None:
+def test_built_in() -> None:
     assert isinstance([], list)
     assert isinstance([1,2,3], list)
     assert isinstance(['a','b'], list)
@@ -555,15 +549,17 @@ def test() -> None:
     assert not isinstance(1, list)
     assert not isinstance('a', list)
 
+def test_user_defined() -> None:
+    from userdefinedlist import list
+
+    assert isinstance(list(), list)
+    assert not isinstance([list()], list)
+
 [file copysubclass.py]
 from typing import Any
 class subc(list[Any]):
     pass
 
-[case testUserDefinedList]
+[file userdefinedlist.py]
 class list:
     pass
-
-def test() -> None:
-    assert isinstance(list(), list)
-    assert not isinstance([list()], list)