[sql mode] Removed `commentHash` and `commentSpaceRequired` from `text/x-pgsql`.

Closes #3888
Closes #4063.

mode/sql/sql.js

@@ -368,7 +368,7 @@ CodeMirror.defineMode("sql", function(config, parserConfig) {
     atoms: set("false true null unknown"),
     operatorChars: /^[*+\-%<>!=&|^]/,
     dateSQL: set("date time timestamp"),
-    support: set("ODBCdotTable decimallessFloat zerolessFloat binaryNumber hexNumber nCharCast charsetCast commentHash commentSpaceRequired")
+    support: set("ODBCdotTable decimallessFloat zerolessFloat binaryNumber hexNumber nCharCast charsetCast")
   });
 
   // Google's SQL-like query language, GQL