Use .KATI_RESTAT to reduce unnecessary rebuilds of binaries

When a shared object is rebuilt, all dependent libraries and
executables are rebuilt. Such rebuild is unnecessary when there
is no interface change. With this patch, .toc files will be
generated for all .so files. The rule which generates .toc files
has ninja's restat=1 and .toc files are not changed ninja won't
rebuild dependent targets.

Performance:

$ m && touch bionic/libc/stdio/stdio.c && time m
Before: 1m03s (2563 targets)
After: 21s (90 targets)

Bug: 24597504
Change-Id: Ia5dd950273d143f4e99eee8bef7478f1a94cd138