This is similar in spirit to https://crrev.com/c/2808621, which is to
ensure that no matter what combination of --[no-]enable-{extension} flag
is passed, we end up with a set of supported extensions that make sense.

The 2 rules are:

- If a newer extension is supported (SSE4_2), older extensions are
supported (SSE4_1, SSSE3, SSE3),
- If an older extension is not supported (SSE4_1), new extensions are
not supported (SSE4_2, AVX)

Tests have been added to both ia32 and x64 to check that we follow these
above 2 rules.

We change the ProbeImpl to have a reconciliation step to ensure that we
stick to the 2 rules.

E.g. if --enable-avx --no-enable-sse4-2, we will first set AVX to
supported, then in the second step, fix-up AVX to unsupported. In this
sense, the --no version of the flags take priority. This more accurately
follows the intention of the flags.

Bug: chromium:1195579
Change-Id: I0390f24de9d203fe6bbd4cc02a23771a1f052618
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2818570
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73942}