[turbofan] Skip printing of empty gap moves.
[turbofan] Skip printing of empty gap moves.

R=bmeurer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/812983002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#25878}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh