Port d21de2a4

Original commit message:
Tail calls are matched on the graph, with a dedicated tail call
optimization that is actually testable. The instruction selection can
still fall back to a regular if the platform constraints don't allow to
emit a tail call (i.e. the return locations of caller and callee differ
or the callee takes non-register parameters, which is a restriction that
will be removed in the future).

Also explicitly limit tail call optimization to stubs for now and drop
the global flag.

R=dstence@us.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1114193003

Cr-Commit-Position: refs/heads/master@{#28239}