vm_dump.c (backtrace): on darwin use custom backtrace() to trace beyond _sigtramp. darwin's backtrace can't trace beyond signal trampoline with sigaltstack.
configure.in: check execinfo.h on darwin.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39808 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
vm_dump.c (backtrace): on darwin use custom backtrace() to trace
beyond _sigtramp. darwin's backtrace can't trace beyond signal
trampoline with sigaltstack.
configure.in: check execinfo.h on darwin.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39808 b2dd03c8-39d4-4d8f-98ff-823fe69b080e