Uninitialized property accesses are replaced with SOFT deopts in
TurboFan, but uninitialized JSCall nodes are not, and instead they
just stick around and are also not being inlined because the heurstic
in TurboFan doesn't consider those candidates since their call frequency
is below the threshold. This unifies the behavior and also replaces
uninitialized calls with SOFT deopts, addressing some inconsistency in
optimization behavior as discovered by Brian White of Node for example
here: https://twitter.com/mscdexdotexe/status/879005026202640385

R=jarin@chromium.org
BUG=v8:4551, v8:5267

Review-Url: https://codereview.chromium.org/2956843002
Cr-Commit-Position: refs/heads/master@{#46231}