let ScInterpreter::pStack contain const formula::FormulaToken*

For two reasons:
* introduce a new PushTokenRef() to push an already existing token,
which can be used in several places that currently unnecessarily
copy-construct a new token to be pushed
* prevent unwanted side effects in case a token on the stack would be
fiddled with, which was possible but just by convention wasn't done

Change-Id: I715d81bcba8bdb415af45e889e9f9db1e0ac4888
Reviewed-on: https://gerrit.libreoffice.org/28377
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>
Tested-by: Jenkins <ci@libreoffice.org>

0 files changed, 0 insertions, 0 deletions