Introduce a new TypedOptimization reducer that contains the type
based optimization reduction steps, which are not (directly)
related to lowering JavaScript operators based on types (which is
what JSTypedLowering is supposed to do).

This also addresses a chicken-and-egg problem that we see in the
Octane/Mandreel benchmark where type based constant folding isn't
applied to the numeric comparison operators introduced by the
JSTypedLowering itself, and thus gives up to 10% speedup for the
benchmark.

BUG=v8:5267

Review-Url: https://codereview.chromium.org/2280673003
Cr-Commit-Position: refs/heads/master@{#38928}