Saves about 1.4MB from the generated wasm file. The Brotli size is
basically unchanged (it's actually slightly larger, by 40K), suggesting
that most of the size delta is due to not inlining and other changes
that were easily compressible.
However, it still seems worthwhile to have a smaller final binary, to
reduce parse time and increase likelihood that we fit in the browser's
disk cache. Actual performance appears to be unchanged.
Updates #5142
Signed-off-by: Mihai Parparita <mihai@tailscale.com>