Remove flex and bison debug flags

Summary: Remove --debug from flex and bison unless compiling with DEBUG defined.

Test Plan: Ran arc lint --everything --never-apply-patches --xprofile=profile.json in rP. Compared before and after.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D13969