gcc: pass -force_cpusubtype_ALL for G3 bottle builds, too

Library/Formula/gcc.rb

@@ -82,7 +82,9 @@ class Gcc < Formula
 
     # Otherwise libstdc++ will be incorrectly tagged with cpusubtype 10 (G4e)
     # https://github.com/mistydemeo/tigerbrew/issues/538
-    ENV.append_to_cflags "-force_cpusubtype_ALL" if Hardware::CPU.family == :g3
+    if Hardware::CPU.family == :g3 || ARGV.bottle_arch == :g3
+      ENV.append_to_cflags "-force_cpusubtype_ALL"
+    end
 
     if MacOS.version < :leopard
       ENV["AS"] = ENV["AS_FOR_TARGET"] = "#{Formula["cctools"].bin}/as"