tgsi: use separate structure for indirect address v2

tgsi: use separate structure for indirect address v2

To further improve the optimization of source and destination
indirect addressing we need the ability to store a reference
to the declaration of the addressed operands.

Since most of the fields in tgsi_src_register doesn't apply for
an indirect addressing operand replace it with a separate
tgsi_ind_register structure and so make room for extra information.

v2: rename Declaration to ArrayID, put the ArrayID into () instead of []

Signed-off-by: Christian König <christian.koenig@amd.com>