This adds basic support for decoding catch-all expressions as part of a
try block. Note that control flow and code generation support is still
missing.

R=clemensh@chromium.org
TEST=unittests/FunctionBodyDecoderTest.TryCatchAll
BUG=v8:8091

Change-Id: I10a1aa3e3e0418e0a04965e8318c94f449a00bb4
Reviewed-on: https://chromium-review.googlesource.com/c/1268059
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56444}