rubinius/rubinius — pull request #1235 by ghazel (2011-10-11 23:04:06+00:00)
Title: Thread#backtrace implementation

(resubmitted because of the need for re-basing and the Github error on #1074)

Related to #1073.

This patch adds Thread#backtrace.

I copied the call_frame acquisition code from Thread#context, and the mri_backtrace code from Kernel#caller.