Update build-tools to ab/3418418

This updates ninja to 1.7.1, with the interesting features:
 * Adds the concept of implicit outputs
 * Makes dupbuild=err work again

Test: m -j
Change-Id: I464c88309236e2374d9fb1a9bf46aa012014fbc3
11 files changed
tree: bd62da78b32d1608fce42260ec601a911108c754
  1. darwin-x86/
  2. linux-x86/
  3. build-prebuilts.sh
  4. manifest.xml