Port 974721c6

Original commit message:
    Introduce a ResumeGeneratorTrampoline, which does the actual stack state
    reconstruction (currently always restores a fullcodegen frame), and
    introduce appropriate TurboFan builtins for %GeneratorPrototype%.next,
    %GeneratorPrototype%.return and %GeneratorPrototype%.throw based on
    this native builtin.

    Also unify the flooding in case of step-in to always work based on
    JSFunction and remove the special casing for JSGeneratorObject.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, mbrandy@us.ibm.com, michael_dawson@ca.ibm.com, bjaideep@ca.ibm.com
BUG=chromium:513471
LOG=n

Review URL: https://codereview.chromium.org/1870483002

Cr-Commit-Position: refs/heads/master@{#35316}