Added bare functions to values clause

src/sqlfluff/dialects/dialect_ansi.py

@@ -1827,6 +1827,7 @@ class ValuesClauseSegment(BaseSegment):
                     Ref("LiteralGrammar"),
                     Ref("IntervalExpressionSegment"),
                     Ref("FunctionSegment"),
+                    Ref("BareFunctionSegment"),
                     "DEFAULT",  # not in `FROM` clause, rule?
                     ephemeral_name="ValuesClauseElements",
                 )

test/fixtures/dialects/postgres/postgres_insert.sql

@@ -1 +1,2 @@
 INSERT INTO test (id, col1) OVERRIDING SYSTEM VALUE VALUES (1, 'val');
+INSERT INTO foo (bar) VALUES(current_timestamp);

test/fixtures/dialects/postgres/postgres_insert.yml

@@ -3,9 +3,9 @@
 # computed by SQLFluff when running the tests. Please run
 # `python test/generate_parse_fixture_yml.py`  to generate them after adding or
 # altering SQL files.
-_hash: 0a486da74287f772aad5a317403b1c8a0c67d03e811aa65d29a763a305fe5362
+_hash: 563d01a9d3f4d84492323c33e29057117a47da895863eb69e48beccd4bc53a5e
 file:
-  statement:
+- statement:
     insert_statement:
     - keyword: INSERT
     - keyword: INTO
@@ -30,4 +30,22 @@ file:
         - comma: ','
         - literal: "'val'"
         - end_bracket: )
-  statement_terminator: ;
+- statement_terminator: ;
+- statement:
+    insert_statement:
+    - keyword: INSERT
+    - keyword: INTO
+    - table_reference:
+        identifier: foo
+    - bracketed:
+        start_bracket: (
+        column_reference:
+          identifier: bar
+        end_bracket: )
+    - values_clause:
+        keyword: VALUES
+        bracketed:
+          start_bracket: (
+          bare_function: current_timestamp
+          end_bracket: )
+- statement_terminator: ;