Use flat arrays instead of switches for function lookups Current implementation of built in function lookup uses autogenerated switch statements. Instead, use the perfect hash mapping to have the lookup use arrays instead. This will improve runtime performance. Bug: angleproject:3805 Change-Id: I6d0ba62d79abd53a7fe818fe675282800781f256 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1756883 Commit-Queue: Clemen Deng <clemendeng@google.com> Reviewed-by: Geoff Lang <geofflang@chromium.org>