nir/repair_ssa: More agressively insert deref casts

Instead of just handling broken derefs, also handle texture and intrinsic instruction sources. This fixes a new CTS test:

dEQP-VK.graphicsfuzz.function-with-uniform-return

Fixes: 1005272a "nir/repair_ssa: Insert deref casts when needed" Closes: #2832 (closed)