Fixes race condition during hyperlinking

Calling `Symbol.toString` outside of the Presentation Compiler Thread  can
result in a race condition, as demonstrated by the stacktrace in the ticket.

Fix #1002352

(cherry picked from commit 9aa7c8d43f20aac70d6fe4b752576a4e7b8d300c)
Merge pull request #875 from skyluc/issue/bp-1002352

Fixes race condition during hyperlinking