This adapts the inlining logic to allow for inlining based solely on a
statically known underlying SharedFunctionInfo instead of a concrete
closure of the call target.

In cases where the closure is known, its bound context is constant
promoted just as before. In the new cases where only the SFI for an
entire class of closures is known, we use the dynamic SSA-value of the
bound context.

R=bmeurer@chromium.org
BUG=v8:2206

Review-Url: https://codereview.chromium.org/2626783003
Cr-Commit-Position: refs/heads/master@{#42968}