openfimg: compiler: Represent operands as vectors

This is needed to make SSA represent properly operations on vector
components, which are now represented as single unrelated scalars. In
addition, variables are now handled as a different register type,
because OF_IR_REG_R will be used after register assignment for physical
temporary registers.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
openfimg: compiler: Fix missing MAD dst register in LRP emulation

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
openfimg: compiler: Reimplement dead code elimination properly

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
openfimg: compiler: Dump SSA data in post-optimize AST dump

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>