nir: Unroll loops with multiplication and left shift incrementation
Calculate number of iterations for loops, where incrementation is done by multiplication.
Multiplication by power of two may be transformed to left shift for integers, thereof requires separate algorithm.
No shader-db changes were observed.
Signed-off-by: Yevhenii Kolesnikov email@example.com
This optimisation can be reproduced on tests in piglit!130 (merged)