Ok I think I figured out how to make this AU thing work with NO PATCHES and JUCE 3.2.0.
- JUCE 3.2.0 release build.
- Latest VST3 SDK (3.6.5) from Stienberg.
- xCode 7.
- Install Apple's Core Audio Utility Classes in "Developer/Extra" folder of xCode package.
- Set OSX base SDK to default
- Set SDK and compatibility to 10.7.
- C++ language standard -> C++ 11
- C++ Library -> LLVM libc++
This runs fine for me with no fixes or patches.