panfrost: Make sure bundle.instructions[] contains valid instructions

Add an assert() in schedule_bundle() to make sure all instruction
pointers in bundle.instructions[] are valid.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>

src/panfrost/midgard/midgard_schedule.c

@@ -562,6 +562,7 @@ schedule_bundle(compiler_context *ctx, midgard_block *block, midgard_instruction
 
         midgard_instruction *uins = ins;
         for (; packed_idx < bundle.instruction_count; ++packed_idx) {
+                assert(&uins->link != &block->instructions);
                 bundle.instructions[packed_idx] = uins;
                 uins = mir_next_op(uins);
         }