configure.ac: fix rb_cv_gcc_compiler_cas
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62765 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
configure.ac: fix rb_cv_gcc_compiler_cas
for multiple AC_CACHE_CHECK. in one check, select by different
values.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62765 b2dd03c8-39d4-4d8f-98ff-823fe69b080e