Add 'some' Ada reserved word (#1581)

The some Ada reserved word is available since Ada 2012, it is used in the same context as the any keyword.
See RM 2.9 - Reserved Words https://www.adaic.org/resources/add_content/standards/12rm/html/RM-2-9.html for a list of keywords (with this inclusion, all are covered if I'm not mistaken)
and for usage example
See RM 4.5.8 - Quantified expressions  https://www.adaic.org/resources/add_content/standards/12rm/html/RM-4-5-8.html

pygments/lexers/pascal.py

@@ -563,9 +563,9 @@ class AdaLexer(RegexLexer):
                 'exception', 'exit', 'interface', 'for', 'goto', 'if', 'is', 'limited',
                 'loop', 'new', 'null', 'of', 'or', 'others', 'out', 'overriding',
                 'pragma', 'protected', 'raise', 'range', 'record', 'renames', 'requeue',
-                'return', 'reverse', 'select', 'separate', 'subtype', 'synchronized',
-                'task', 'tagged', 'terminate', 'then', 'type', 'until', 'when',
-                'while', 'xor'), prefix=r'\b', suffix=r'\b'),
+                'return', 'reverse', 'select', 'separate', 'some', 'subtype',
+                'synchronized', 'task', 'tagged', 'terminate', 'then', 'type', 'until',
+                'when', 'while', 'xor'), prefix=r'\b', suffix=r'\b'),
              Keyword.Reserved),
             (r'"[^"]*"', String),
             include('attribute'),