LibC: Fix huge libc.a file size due to the use of `llvm-ar -q`

Before this change, we would generate the static C library by running
the command `ar -qcs` to collect the various `*.o` files into a single
archive.

The `q` option stands for "quick append", which simply appends new files
to the archive, without replacing any pre-existing entries for the same
file. The problem with this is obvious: each LibC rebuild would add
approximately 1 MB (the size of a cleanly built libc.a) to the size of
the file. It got so bad on my machine that the total file size ended up
being 3 gigabytes.

Note that this did not affect the GNU toolchain, because, as the `ar(1)`
manpage says:
> Note - GNU ar treats the command qs as a synonym for r - replacing
> already existing files in the archive and appending new ones at the
> end.

0 files changed, 0 insertions, 0 deletions