Otherwise it sometimes, but not always, causes an error:
RPython traceback:
File "rpython_jit_metainterp_compile.c", line 20472, in send_loop_to_backend
File "rpython_jit_backend_x86_assembler.c", line 1818, in Assembler386_assemble_loop
File "rpython_jit_backend_x86_regalloc.c", line 293, in RegAlloc_prepare_loop
File "rpython_jit_backend_x86_regalloc.c", line 909, in RegAlloc__prepare
File "rpython_jit_backend_llsupport_regalloc.c", line 4706, in compute_vars_longevity
Fatal RPython error: AssertionError
/home/travis/build.sh: line 236: 7300 Aborted