[turbofan] Use the SharedInfo only if we have it in the code generator.
[turbofan] Use the SharedInfo only if we have it in the code generator.

R=bmeurer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1303953007

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#30445}

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