intel/ir: Represent physical edge of ELSE instruction.

This edge doesn't exist in the original scalar program, but it
represents a potential control flow path the EU will take in cases
where the condition isn't uniform across channels of the same SIMD
thread.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>

src/intel/compiler/brw_cfg.cpp

@@ -221,6 +221,7 @@ cfg_t::cfg_t(exec_list *instructions)
 	 next = new_block();
          assert(cur_if != NULL);
          cur_if->add_successor(mem_ctx, next, bblock_link_logical);
+         cur_else->add_successor(mem_ctx, next, bblock_link_physical);
 
 	 set_next_block(&cur, next, ip);
 	 break;