This reverts commit 23728729, reversing
changes made to 3e4547f5.

If people have `HOMEBREW_RUBY_PATH` set then things explode in a rather
confusing fashion. Instead, run `bundle` for them with the arguments
that they'd want.

Also, move `macho` requires into the module itself; it's a pain having
to do everything for Bundler before requiring `pathname` which is a core
Ruby class.

Homebrew's actually ended up using a fair few gems. While we want to
avoid Bundler at runtime (and this PR still does that, in fact uses
Bundler even less at runtime than it did before) writing our own version
to use at build-time seems redundant.

Prevents namespace conflict with vendored ruby-macho.

This allows us to filter out weak linkages during audits, preventing
a false error from occurring when the dylib cannot be found.

Prevents namespace conflict with vendored ruby-macho.

This allows us to filter out weak linkages during audits, preventing
a false error from occurring when the dylib cannot be found.

Disable check for $HOMEBREW_NO_RUBY_MACHO now that no alternative exists.

Closes #656.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

MachOFile#cputype now returns a Symbol.

Both the `CctoolsMachO` and `RubyMachO` module implement a common set of
methods that simplify querying `mach_data`. Move these into a shared
module, that gets included after either of these implementations is
loaded and included in `Pathname`.

The current approach of suppressing all output regardless of what the
error is makes it very hard to debug any issues and misread but valid
Mach-O files will be silently interpreted as non-Mach-O files instead.

Prefer to fail if we are a Homebrew developer or running on the bot
(`HOMEBREW_DEVELOPER=1`), so that problems will be noticed and fixed
before the silent failure leads to hard-to-diagnose user problems.

Closes Homebrew/homebrew#48817.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

- and branch for dylib_id_and_dylibs
- add branches for dylib id changing and change_install_name
- rename MachO module to HomebrewMachO to prevent namespace clashes
  with MachO in ruby-macho. this will eventually be replaced entirely
  with direct calls to ruby-macho methods
- break ruby-macho implementation out into separate RubyMachO module,
  and include either RubyMachO or CctoolsMachO (the original
  implementation) based on the HOMEBREW_RUBY_MACHO env var
- move ArchitectureListExtension and RubyMachO into separate files
- create {ruby_,cctools_,,}relocate.rb for isolation of different
  methods of mach-o relocation (ruby-macho vs. cctools)
- fill in require_install_name_tool? for ruby_relocate.rb
- rename {ruby_,cctools_,,}relocate.rb to keg, isolate requires in
  os/mac

Closes Homebrew/homebrew#45001.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>