This fixes corner cases where the start offsets of exception handler
regions within the handler table fall together. This assumption was
based on full-codegen code and no longer holds with the interpreter.
The tables however are still well nested and code has been added to
verify that in debug mode.

R=rmcilroy@chromium.org
BUG=v8:4674
LOG=n

Review URL: https://codereview.chromium.org/1633573002

Cr-Commit-Position: refs/heads/master@{#33495}