Implement the required but unused __aeabi_unwind_cpp_* functions in the
trampoline kernel.
The compiler argument -mno-apcs-frame has no meaning when using EABI as we
will use aapcs frames, not apcs frames.
Move the __aeabi_unwind_cpp_pr{0,1,2} functions to libkern so they can be
referenced in a non-debug kernel.
Add END to ARM libkern assembly functions