[turbofan] Remove obsolete --turbo-try-catch flag.

[turbofan] Remove obsolete --turbo-try-catch flag.

This removes the aforementioned flag which has been on by default for a
while now. Note that this does not control optimization decisions, only
the last-resort bailout in the graph builder.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1335543002

Cr-Commit-Position: refs/heads/master@{#30673}