Exempt all the names found in type annotations from unused-import

The previous code was assuming that only ``typing`` names need to be
exempted, but we need to do that for the rest of the type comment
names as well.

Close #3112

ChangeLog

@@ -2,6 +2,19 @@
 Pylint's ChangeLog
 ------------------
 
+What's New in Pylint 2.4.4?
+===========================
+Release date: TBA
+
+* Exempt all the names found in type annotations from ``unused-import``
+
+  The previous code was assuming that only ``typing`` names need to be
+  exempted, but we need to do that for the rest of the type comment
+  names as well.
+
+  Close #3112
+
+
 What's New in Pylint 2.4.3?
 ===========================
 

pylint/checkers/variables.py

@@ -1693,7 +1693,6 @@ def _store_type_annotation_node(self, type_annotation):
         self._type_annotation_names.extend(
             annotation.name
             for annotation in type_annotation.nodes_of_class(astroid.Name)
-            if annotation.name in TYPING_NAMES
         )
 
     def _store_type_annotation_names(self, node):

tests/functional/u/unused_typing_imports.py

@@ -7,6 +7,7 @@
 
 import re
 import typing
+from datetime import datetime
 from typing import (
     Any,
     Callable,
@@ -63,3 +64,9 @@ def function(arg1,  # type: Iterable
     # type: (...) -> Sequence
     """docstring"""
     print(arg1, arg2)
+
+
+def magic(alpha, beta, gamma):
+    # type: (str, Optional[str], Optional[datetime]) -> Any
+    """going strong"""
+    return alpha, beta, gamma