Class member initializer functions do not support lazy compilation, so
change FunctionLiteral::AllowsLazyCompilation to return false for them.

Change-Id: I38434f3a7e8c88af3f407cf19308fc3862ec4403
Reviewed-on: https://chromium-review.googlesource.com/c/1470103Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59588}