r600g: drop compiler stuff and switch over dumb tgsi assembler

r600g: drop compiler stuff and switch over dumb tgsi assembler

Writing a compiler is time consuming and error prone in
order to allow r600g to further progress in the meantime
i wrote a simple tgsi assembler, it does stupid thing but
i would rather keep the code simple than having people
trying to optimize code it does.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>