Unwind: prevent unw_get_proc_info from returning stale data

If unwind info is not available at the current IP, unw_get_proc_info should
return a zero-filled structure rather than the info of the previous IP.

This change also makes unw_get_proc_info return UNW_ENOINFO instead of

Patch by Amanieu d'Antras!

git-svn-id: https://llvm.org/svn/llvm-project/libunwind/trunk@372407 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed