Amber test validate_phi_src
Issue found using graphicsfuzz.
Device: AMD RADV NAVI10 (LLVM 10.0.1) Driver: Mesa 20.1.6 (git-11a9fde2) (LLVM 10.0.1)
Running test.amber results: validate_phi_src. On success the test should draw red image:
Test also crashes on mesa 20.1.7.
However it causes different error on mesa master: nir_validate_shader, exec_list_length(&instr->srcs) == state->block->predecessors->entries.