AngelScript in C++ Builder XE3 with x64 support

I don't see why not. C++ Builder is already supported for Win32.

Hopefully C++ Builder uses a MSVC compatible ABI for Win64, so it may just be a matter of configuring as_config.h appropriately for C++ Builder and Win64.

I have a lot of tests in the test_feature project (you'll find it in the svn) that are designed especifically for testing the native calling convention. If you wish to try to add the support I suggest you start by updating the as_config.h for C++ Builder and Win64 based on MSVC/Win64 and then running these tests to see what works or not.

Let me know what the results are and I'll help to identify what further changes are needed.