libc x86: Remove strcat.S

This file is never used.

Change-Id: Iae4bba4a5a12a86a775af05e7477fb7b6511480b
Merge "libc x86: Remove strcat.S"
Add strncpy FORTIFY_SOURCE tests.

Change-Id: Id108b1d72b44d7e5fb911268e80bbdf896808f60
Merge "Add strncpy FORTIFY_SOURCE tests."
Merge remote-tracking branch 'aosp/master'