Fix #80521: Parameters with underscores no longer recognized

We have to use the proper value for the bitmask.

NEWS

@@ -9,6 +9,10 @@ PHP                                                                        NEWS
   . Fixed bug #67983 (mysqlnd with MYSQLI_OPT_INT_AND_FLOAT_NATIVE fails to
     interpret bit columns). (Nikita)
 
+- PDO_Firebird:
+  . Fixed bug #80521 (Parameters with underscores no longer recognized). (cmb,
+    Simonov Denis)
+
 07 Jan 2021, PHP 8.0.1
 
 - Core:

ext/pdo_firebird/firebird_driver.c

@@ -136,7 +136,7 @@ static const char classes_array[] = {
 	/* 092  \  */ 0,
 	/* 093  ]  */ 0,
 	/* 094  ^  */ 0,
-	/* 095  _  */ 65, /* CHR_IDENT | CHR_INTRODUCER */
+	/* 095  _  */ 68, /* CHR_IDENT | CHR_INTRODUCER */
 	/* 096  `  */ 0,
 	/* 097  a  */ 37, /* CHR_LETTER | CHR_IDENT | CHR_HEX */
 	/* 098  b  */ 37, /* CHR_LETTER | CHR_IDENT | CHR_HEX */

ext/pdo_firebird/tests/bug_80521.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Bug #80521 (Parameters with underscores no longer recognized)
+--SKIPIF--
+<?php require('skipif.inc'); ?>
+--FILE--
+<?php
+require 'testdb.inc';
+
+$dbh->exec("CREATE TABLE bug80521 (foo INTEGER)");
+var_dump($dbh->prepare("SELECT foo FROM bug80521 WHERE foo = :foo_bar"));
+?>
+--EXPECTF--
+object(PDOStatement)#%d (1) {
+  ["queryString"]=>
+  string(45) "SELECT foo FROM bug80521 WHERE foo = :foo_bar"
+}
+--CLEAN--
+<?php
+require 'testdb.inc';
+$dbh->exec("DROP TABLE bug80521");
+?>