var_dump has differing precision between PHP 7 and 8

This is probably due to the locale-neutral float conversion.
var_dump will show an extra 3 digits of precisions varying, but
var_export seems to always show the remaining 3 digits. Many of the
other conversion functions could have been used instead if we did
not want to show the last three digits.

tests/test_RealDataType.phpt

@@ -21,7 +21,8 @@ if ($conn) {
 	$res = db2_exec($conn, "SELECT tz_offset from test1R");
 	
 	while ($row = db2_fetch_both($res)) {
-		var_dump($row);
+		echo(var_export($row[0], true) . "\n");
+		echo(var_export($row["TZ_OFFSET"], true) . "\n");
 	}
 	
 	// Dropping the test table.
@@ -33,9 +34,5 @@ if ($conn) {
 }
 ?>
 --EXPECT--
-array(2) {
-  ["TZ_OFFSET"]=>
-  float(-2.3399999141693)
-  [0]=>
-  float(-2.3399999141693)
-}
+-2.3399999141693115
+-2.3399999141693115