[ubsan] Fall back to the fast unwinder when print_stacktrace=1
This makes it possible to get stacktrace info when print_stacktrace=1 on
Darwin (where the slow unwinder is not currently supported [1]). This
should not regress any other platforms.
[1] The thread about r300295 has a relatively recent discusion about
this. We should be able to enable the existing slow unwind functionality
for Darwin, but this needs more testing.
Differential Revision: https://reviews.llvm.org/D32517
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@301839 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit a88ac2959bf2987b64e38382a607e991c617dd9d)
3 files changed
