The UMA sampling profiler needs a way to detect the beginning of the
embedded builtins code range; a plain symbol is not enough, but a
function symbol should be good.

This changes (x64)

 v8_Default_embedded_blob_code_data_:

to

 v8_Default_embedded_blob_code_data_:
 .type v8_Default_embedded_blob_code_data_, @function
 .size v8_Default_embedded_blob_code_data_, 0

Bug: v8:6666
Change-Id: I5dce3aaca0f36e15ad4339e20fbbdc76282a289e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2450058
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70330}