patch 9.2.0735: [security]: arbitrary Ex command execution during C omni-completion

patch 9.2.0735: [security]: arbitrary Ex command execution during C omni-completion

Problem:  [security]: With C omni-completion, a crafted tags file can execute
          arbitrary Ex commands when completing a struct/union member
          (cipher-creator)
Solution: Escape the type field before inserting it into the :vimgrep
          pattern so it cannot close the pattern and start a new command
          (Hirohito Higashi).

Github Security Advisory:
https://github.com/vim/vim/security/advisories/GHSA-mf92-v4xw-j45x

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>"
Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>