Use perfect-hash module in gen_builtin_symbols.py The script currently takes ~4 minutes to run Using this module instead of manually hashing will improve runtime significantly Bug: angleproject:3747 Change-Id: I7e2d2ef5bbfd136b0299d571e0acc11f334c80b5 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1724667 Commit-Queue: Clemen Deng <clemendeng@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>