add bionic scanf source files

Change-Id: I5dbec21fbba74079fa311fa376e7bbaaa6728984
scanf("%a") wip. does not quite work yet, but fairly far along

Change-Id: I2092699ea9e0c7f16d5d1e0b3a84fabb9eea520f
scanf("%a") works!

Change-Id: I12aab6cb8f9bc17586cebf3217fc3efcada4a1ba