tor: use Formula[]
Use Formula[] in example formula
Remove requested? dependency magic
Apply cyclic dependency hack unconditionally
Add set union to Options
Clean up FormulaInstaller#install_dependency
Pass expansion-time build options to install_dependency
Eliminate mutation of Dependency objects
Cache and reuse Dependency objects
xulrunner: depends_on :xcode + specify MacOS.sdk_path Fixes #26846 Closes #26862
xulrunner: add 27.0.1 bottle.