[ruby-cvs:71944] shyouhei:r64852 (trunk): use configure-defined macro instead of __GNUC__

[shyouhei at ruby-lang.org]

shyouhei	2018-09-26 15:16:32 +0900 (Wed, 26 Sep 2018)

  New Revision: 64852

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=64852

  Log:
    use configure-defined macro instead of __GNUC__

  Modified files:
    trunk/include/ruby/ruby.h