Reset utf8_invalid in json scanner

Author: bukka

ext/json/json_scanner.c

@@ -292,6 +292,7 @@ int php_json_scan(php_json_scanner *s)
 			{
 		s->str_start = s->cursor;
 		s->str_esc = 0;
+		s->utf8_invalid = 0;
 		s->utf8_invalid_count = 0;
 		PHP_JSON_CONDITION_SET_AND_GOTO(STR_P1);
 	}

ext/json/json_scanner.re

@@ -209,6 +209,7 @@ std:
 	<JS>["]                  {
 		s->str_start = s->cursor;
 		s->str_esc = 0;
+		s->utf8_invalid = 0;
 		s->utf8_invalid_count = 0;
 		PHP_JSON_CONDITION_SET_AND_GOTO(STR_P1);
 	}