* addr2line.c: Because stdbool.h is a C99 feature, compile error
occurs with some old compilers without specifying C99 options.
Fix compile error with Oracle Solaris Studio 12.4 on Solaris 10.
[Bug #14200] [ruby-dev:50366]
* missing/stdbool.h: Alternative of stdbool.h for C89 compilers.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61326 b2dd03c8-39d4-4d8f-98ff-823fe69b080e