Used Signature API instead of deprecated inspect.getcallargs().

inspect.getcallargs() was deprecated in Python 3.5 and the Signature
API (PEP 362) has better support for decorated functions (by default,
it follows the __wrapped__ attribute set by functools.wraps for
example).

django/db/models/sql/query.py

@@ -1916,9 +1916,8 @@ class Query(BaseExpression):
         group_by = list(self.select)
         if self.annotation_select:
             for alias, annotation in self.annotation_select.items():
-                try:
-                    inspect.getcallargs(annotation.get_group_by_cols, alias=alias)
-                except TypeError:
+                signature = inspect.signature(annotation.get_group_by_cols)
+                if 'alias' not in signature.parameters:
                     annotation_class = annotation.__class__
                     msg = (
                         '`alias=None` must be added to the signature of '

django/template/base.py

@@ -857,8 +857,9 @@ class Variable:
                         try:  # method call (assuming no args required)
                             current = current()
                         except TypeError:
+                            signature = inspect.signature(current)
                             try:
-                                inspect.getcallargs(current)
+                                signature.bind()
                             except TypeError:  # arguments *were* required
                                 current = context.template.engine.string_if_invalid  # invalid method call
                             else: