Add several missing entries to table comma lookahead

src/parser/parse_errors.mlyl

@@ -16,7 +16,7 @@ rule error_message = parse error
   { Error.Use_double_equals (token, $startloc(token), $endloc(token)) }
 
 (* Suggest a missing comma in table entries. *)
-| last = [_ / table_body: table_entry . ...] @ STRING, NUMBER, TRUE, FALSE, NIL
+| last = [_ / table_body: table_entry . ...] @ STRING, NUMBER, TRUE, FALSE, NIL, OSQUARE, OPAREN, IDENT
   {
     let token = (token, $startloc(token), $endloc(token)) in
     Missing_table_comma { comma_pos = $endloc(last); token }

test/parser/t_parse_errors.md

@@ -96,6 +96,7 @@ local function f(a
 ```
 
 ## Missing commas in tables
+We try to detect missing commas in tables, and print an appropriate error message.
 
 ```lua
 return { 1 2 }
@@ -123,6 +124,39 @@ return { 1, 2 3 }
  1 │ return { 1, 2 3 }
    │              ^ Are you missing a comma here?
 ```
+
+This also works with table keys.
+
+```lua
+print({ x = 1 y = 2 })
+```
+
+```txt
+=input: Unexpected identifier in table. [parse:syntax-error]
+   │
+ 1 │ print({ x = 1 y = 2 })
+   │               ^
+   │
+ 1 │ print({ x = 1 y = 2 })
+   │              ^ Are you missing a comma here?
+```
+
+```lua
+print({ ["x"] = 1 ["y"] = 2 })
+```
+
+```txt
+=input: Unexpected `[` in table. [parse:syntax-error]
+   │
+ 1 │ print({ ["x"] = 1 ["y"] = 2 })
+   │                   ^
+   │
+ 1 │ print({ ["x"] = 1 ["y"] = 2 })
+   │                  ^ Are you missing a comma here?
+```
+
+We gracefully handle the case where we are actually missing a closing brace.
+
 ```lua
 print({ 1, )
 ```