Reason for revert:
Fuzzer claims `try { \"\" ; } catch(x) { let x1 = [1,,], x = x; }` causes a crash.
Original issue's description:
> Add errors for declarations which conflict with catch parameters.
>
> Catch parameters are largely treated as lexical declarations in the
> block which contains their body for the purposes of early syntax errors,
> with some exceptions outlined in B.3.5. This patch introduces most of
> those errors, except those from `eval('for (var e of ...);')` inside of
> a catch with a simple parameter named 'e'.
>
> Note that annex B.3.5 allows var declarations to conflict with simple
> catch parameters, except when the variable declaration is the init of a
> for-of statement.
>
> BUG=v8:5112,v8:4231
>
> Committed: https://crrev.com/2907c726b2bb5cf20b2bec639ca9e6a521585406
> Cr-Commit-Position: refs/heads/master@{#37462}
TBR=littledan@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5112,v8:4231
Review-Url: https://codereview.chromium.org/2112223002
Cr-Commit-Position: refs/heads/master@{#37464}
8834d5ecb5