fix(postgres): avoid regex backrefs for cross-engine cast parsing

Author: elpete

models/Grammars/PostgresGrammar.cfc

@@ -342,12 +342,13 @@ component extends="qb.models.Grammars.BaseGrammar" singleton {
         var defaultValue = column.getDefaultValue();
         // Normalize PostgreSQL cast shorthand (value::TYPE) so runtimes that
         // parse ":" for named params don't break schema DDL execution.
-        if ( reFindNoCase( "(.+)::([a-zA-Z_][a-zA-Z0-9_\\[\\]\\.\\s]*)$", defaultValue ) ) {
-            defaultValue = reReplaceNoCase(
-                defaultValue,
-                "^(.+)::([a-zA-Z_][a-zA-Z0-9_\\[\\]\\.\\s]*)$",
-                "CAST(\\1 AS \\2)"
-            );
+        var castMatch = reFindNoCase( "::([a-zA-Z_][a-zA-Z0-9_\\[\\]\\.\\s]*)$", defaultValue, 1, true );
+        if ( castMatch.pos[ 1 ] > 0 ) {
+            var castPosition = castMatch.pos[ 1 ];
+            var castLength = castMatch.len[ 1 ];
+            var valuePart = left( defaultValue, castPosition - 1 );
+            var typePart = right( defaultValue, castLength - 2 );
+            defaultValue = "CAST(#valuePart# AS #typePart#)";
         }
 
         switch ( column.getType() ) {