Specify int bitfield as signed int bitfield

sunc treats int bitfield as unsigned int.
This commit will fix build failure on sunc.

* http://rubyci.s3.amazonaws.com/solaris10-sunc/ruby-master/log/20230617T100003Z.fail.html.gz
* http://rubyci.s3.amazonaws.com/solaris11-sunc/ruby-master/log/20230617T090011Z.fail.html.gz

1 files changed, 2 insertions, 2 deletions

diff --git a/parse.y b/parse.y
index 0e1717e7c4..dac6700a00 100644
--- a/parse.y
+++ b/parse.y
@@ -441,8 +441,8 @@ struct parser_params {
     rb_parser_config_t *config;
 #endif
     /* compile_option */
-    int frozen_string_literal:2; /* -1: not specified, 0: false, 1: true */
-    int coverage_enabled:2; /* -1: not specified, 0: false, 1: true */
+    signed int frozen_string_literal:2; /* -1: not specified, 0: false, 1: true */
+    signed int coverage_enabled:2; /* -1: not specified, 0: false, 1: true */
 
     unsigned int command_start:1;
     unsigned int eofp: 1;