Fix some cedet compilation warnings pertaining to semantic/db

* lisp/cedet/ede/config.el (semantic/db)
(ede-preprocessor-map): Ditto.

* lisp/cedet/ede/cpp-root.el (semantic/db): Ditto.

* lisp/cedet/ede/emacs.el (semantic/db): Ditto.

* lisp/cedet/ede/linux.el (semantic/db): Require to avoid warnings
about unknown slot lexical-table, and remove declare-functions
from the now-required semantic/db.
1 job for master in 90 minutes and 2 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
failed #2157
test-all

01:30:02

 
Name Stage Failure
failed
test-all Test The script exceeded the maximum execution time set for the job
make -C test check-expensive
make[1]: Entering directory '/builds/emacs/emacs/test'
rm -f ./*.tmp
make[2]: Entering directory '/builds/emacs/emacs/test'
make[3]: Entering directory '/builds/emacs/emacs/test'
ELC lisp/net/tramp-tests.elc
GEN lisp/net/tramp-tests.log
Pulling docker image gitlab/gitlab-runner-helper:x86_64-f100a208 ...
ERROR: Job failed: execution took longer than 1h30m0s seconds