port 593c655a (r30816).

original commit message:

    This removes the weird COMPARE and COMPARE_STRONG JavaScript builtins
    and replaces them with a proper C++ implementation in Object::Compare
    and appropriate wrappers Object::LessThan, Object::GreaterThan, and
    friends that are intended to be used by a true/false returning CompareIC
    in the future, as well as the interpreter.  As a short-term solution we
    provide %Compare and %Compare_Strong entry points for the current
    CompareIC that return the appropriate integer values expected by
    fullcodegen currently.

    Now the Abstract Relational Comparison is also using the correct
    ToPrimitive implementation, which properly supports @@toPrimitive.

BUG=

Review URL: https://codereview.chromium.org/1353343002

Cr-Commit-Position: refs/heads/master@{#30844}