for darwin (this header is missing in the iOS SDK)
* eval_intern.h: check HAVE_CRT_EXTERNS_H before including crt_externs.h, if
not defined, include missing/crt_externs.h instead
* hash.c: ditto
* missing/setproctitle.c: ditto
* missing/crt_externs.h: declare _NSGetEnviron() function and define environ
for iOS
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38644 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
charliesome