lli/RecordingMemoryManager: Free allocated sections in the destructor to satisfy --vg-leak!

FIXME: It could be generalized in MemoryManager.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173349 91177308-0d34-0410-b5e6-96231b3b80d8
unittests/SupportTests/Initialize.MultipleThreads: Appease --vg-leak to allocate stack explicitly for glibc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173350 91177308-0d34-0410-b5e6-96231b3b80d8