Unhide __cxa_begin_cleanup and __cxa_type_match needed by libgcc.a

Refresh only sources/cxx-stl/gnu-libstdc++ to NDK r8d+ with the following
https://android-review.googlesource.com/#/c/52900
https://android-review.googlesource.com/#/c/52961

Also see
  https://android-review.googlesource.com/#/c/52981
  https://android-review.googlesource.com/#/c/53006
  Internal bug ref: b/8247455

Change-Id: I864f33e389324a59deea8c8ca81cdf6597bf9620
69 files changed
tree: c680c5d98d789c75923957058126604e7041b5e8
  1. 4/
  2. 5/
  3. 6/
  4. 7/
  5. 8/
  6. Android.mk
  7. CleanSpec.mk