Trampoline and assembly fixes for ARM64

Trampolines need a jump, not a call. Expose br in the ARM64
assembler to allow this.

The resolution trampoline is called with the Quick ABI, and will
continue to a Quick ABI function. Then the method pointer must be
in x0.

Change-Id: I4e383b59d6c40a659d324a7faef3fadf0c890178
4 files changed