Fix dlclose for libraries with thread_local dtors

Introduce new flag to mark soinfo as TLS_NODELETE when
there are thread_local dtors associated with dso_handle
belonging to it.

Test: bionic-unit-tests --gtest_filter=dl*
Test: bionic-unit-tests-glibc --gtest_filter=dl*
Bug: https://github.com/android-ndk/ndk/issues/360
Change-Id: I724ef89fc899788f95c47e6372c38b3313f18fed