This should improve the debugging experience since backtraces will
list the exact builtin instead of just 'embedded_blob'. An example
gdb backtrace:

 #0  <snip address> in Builtins_RegExpPrototypeExec ()
 #1  <snip address> in Builtins_ArgumentsAdaptorTrampoline ()
 <snip further frames>

Bug: v8:6666, v8:7722
Change-Id: Iafc995779903e7d7a980d66e7dad42938ac7d29e
Reviewed-on: https://chromium-review.googlesource.com/1145183Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54598}