[ruby-cvs:78990] a04c535967 (master): Use __func__ as rb_cv_function_name_string on OpenBSD

Jeremy Evans	2019-12-28 17:25:11 +0900 (Sat, 28 Dec 2019)

  New Revision: a04c535967

  https://github.com/ruby/ruby/commit/a04c535967

  Log:
    Use __func__ as rb_cv_function_name_string on OpenBSD
    
    The use of RUBY_WERROR_FLAG causes this test to fail on OpenBSD
    platforms that use the binutils linker (ld.bfd) instead of the
    llvm linker (ld.lld), due to warnings added to the binutils linker
    in OpenBSD.
    
    Removing the RUBY_WERROR_FLAG would probably also fix it, but that
    would affect other platforms.
    
    This should also be backported to Ruby 2.7.
    
    Analysis and similar fix recommended by George Koehler.

  Modified files:
    configure.ac