Move superenv.rb to extend/ENV/super.rb
Move common ENV methods to a shared module
Rename HomebrewEnvExtension to Stdenv
More robust implementation of ENV.with_build_environment
No longer call ENV.userpaths! in requirements

Instead we use which with a custom PATH.
Initial tests for superenv sanity
Remove ENV.expand_xcrun

This method is currently unused and after inspecting the git history, it
appears it may never have been used at all.
audit: activate ENV extensions
Use File::PATH_SEPARATOR globally instead of ':'

On Unix, the path separator is ':', whereas on Windows,
it is ';'. This is the first of a series of patch to bring
macbrew's and winbrew's codebases closer together.

The main places the magic constant ':' was being used were:
  - the $PATH environment variable
  - CMAKE-related environment variables
  - pkg-config related environment variables

Closes #21921.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
which in requirements always uses ORIGINAL_PATHS now

Fixes #22002.
Fix typo
superbin -> Superenv.bin

Fixes #22000.
SUPPORTERS: add final list.
Add ENV.append_path
Use ENV.append_path
Use ENV.prepend_path
Add tests for ENV.{append,prepend}_path
Use ENV.{append,prepend}_path in formulae
denominator 3.6.0

Closes #22011.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
icu4c: add HEAD

This allows for building on 10.9, as upstream changes are available that have yet to be released.

Closes #22010.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>