ArchDefaultUnwindPlan plug-in interfaces are now cached per architecture
instead of being leaked for every frame.
Split the ArchDefaultUnwindPlan_x86 into ArchDefaultUnwindPlan_x86_64 and
ArchDefaultUnwindPlan_i386 interfaces.
There were sporadic crashes that were due to something leaking or being
destroyed when doing stack crawls. This patch should clear up these issues.
llvm-svn: 125541