Add permit_weak_imports directive

Library/Homebrew/extend/ENV/shared.rb

@@ -293,6 +293,8 @@ def warn_about_non_apple_gcc(name)
 
  def permit_arch_flags; end
 
+ def permit_weak_imports; end
+
  private
 
  def cc=(val)

Library/Homebrew/extend/ENV/super.rb

@@ -78,6 +78,7 @@ def setup_build_environment(formula = nil)
  # g - Enable "-stdlib=libc++" for clang.
  # h - Enable "-stdlib=libstdc++" for clang.
  # K - Don't strip -arch <arch>, -m32, or -m64
+ # w - Pass -no_weak_imports to the linker
  #
  # On 10.8 and newer, these flags will also be present:
  # s - apply fix for sed's Unicode support

Library/Homebrew/extend/os/mac/extend/ENV/std.rb

@@ -146,4 +146,8 @@ def x11
 
  append "CFLAGS", "-I#{MacOS::X11.include}" unless MacOS::CLT.installed?
  end
+
+ def permit_weak_imports
+ remove "LDFLAGS", "-Wl,-no_weak_imports"
+ end
 end

Library/Homebrew/extend/os/mac/extend/ENV/super.rb

@@ -107,6 +107,10 @@ def set_x11_env_if_installed
  ENV.x11 = MacOS::X11.installed?
  end
 
+ def permit_weak_imports
+ remove "HOMEBREW_CCCFG", "w"
+ end
+
  # These methods are no longer necessary under superenv, but are needed to
  # maintain an interface compatible with stdenv.
  alias_method :macosxsdk, :noop