Adding some wasm committers to top level OWNERS.

Following the existing model where most committers are top-level OWNERS, this enables easier boilerplate changes to the V8 build environment and tests in the PST time-zone.

R=danno@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2101423002
Cr-Commit-Position: refs/heads/master@{#37337}

OWNERS

 adamk@chromium.org
 ahaas@chromium.org
+bbudge@chromium.org
+binji@chromium.org
 bmeurer@chromium.org
+bradnelson@chromium.org
 cbruni@chromium.org
 danno@chromium.org
 epertoso@chromium.org
@@ -15,6 +18,7 @@ machenbach@chromium.org
 marja@chromium.org
 mlippautz@chromium.org
 mstarzinger@chromium.org
+mtrofin@chromium.org
 mvstanton@chromium.org
 mythria@chromium.org
 neis@chromium.org