Revert "FormulaInstaller: make mode reader methods private"

This reverts commit 44bff238434a48c4a8531bc2d1a29c81f18f8fab.

Conflicts:
	Library/Homebrew/formula_installer.rb

Fixes #33882.
alpine 2.11

Merges Alpine-chappa into Alpine, following Debian & Ubuntu’s lead,
adds my patch for the Yosemite build failure.

Closes #33634.
alpine: update 2.11_2 bottle.