This CL adds V8_EXPORT_PRIVATE declarations needed for component build with
enabled MSAN on Linux.

Change-Id: Ia79ca117b8f5128f8e681b0574066e86f2407a84
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1893342Reviewed-by: Simon Zünd <szuend@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64735}