Allow builds from source with macOS' (Xcode's) `bison`

[zbeekman]

Homebrew doesn't like it when you use a non-native tool (e.g., GNU version) instead of the version provided by macOS/Xcode. Investigate building with native bison provided on macOS.

$ brew audit --strict --online --new-formula bic
bic:
  * Dependency 'bison' is provided by macOS; please replace 'depends_on' with 'uses_from_macos'.