Move Android ucontext.h out of third_party. am: 757aea1419 am: 5df34462eb
am: 64c5e351cc

Change-Id: I5116ff2a5adb3593734ec8a3c0fde40fb3ed0272
tree: ef89efcab51ef149dbe7fe3f758c8751a234a490
  1. LICENSE.TXT