glsl-4.00: Add tests for loops with mul and ishl incrementation

Loops with iterator, increased by multiplication, can potentially be unrolled. Multiplication by power of 2 may be replaced by left shift for integers, therefore should be a separate case. 64 bit numbers are computed in a separate paths so should be tested as well.

This tests' results are based on the correctness of computations and expected to always be true.

Signed-off-by: Yevhenii Kolesnikov yevhenii.kolesnikov@globallogic.com