Mark Function::GetDisplayName() as deprecated, scheduled for removal
with M92.

Bug: chromium:1177685, chromium:17356
Change-Id: Iedb905d2d5ab6f8ec95f47bbc982e4f03891fd48
Doc: https://bit.ly/devtools-function-displayName-removal
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2690601Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72710}