GAbi++: Add one time construction support
David 'Digit' Turner authored
This patch adds sources/cxx-stl/gabi++/src/one_time_construction.cc
and removes the dependency on libstdc++ from GAbi++

The implementation is based on pthread which is always provided by
the C library on Android (the latter is always linked to generated
binaries, so there is no need to list it in LOCAL_EXPORT_LDLIBS).

+ Add unit test to check that one-time-construction works properly.

Change-Id: Ic4af9f19814cf9efd7caa60bc84e9c03fc4bf656
26cc9e31