This CL solves recent clang compilation error:
"src/wasm/function-body-decoder.cc:1418:18: error: comparison of two
values with different enumeration types in switch statement
('v8::internal::wasm::ControlKind' and 'ControlKind')"

Bug: 
Change-Id: I6cb32bb3d42256a80d6f9222f5450ee93ce1021a
Reviewed-on: https://chromium-review.googlesource.com/615247Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47391}