The change in commit v3.5.0-rc1~198^2 (Ninja: Always re-run custom
commands that have symbolic dependencies, 2015-11-19) broke the
byproducts feature added by commit v3.2.0-rc1~340^2~2 (Add an option for
explicit BYPRODUCTS of custom commands, 2014-11-13) when SYMBOLIC
outputs also appear.  This case occurs with AUTORCC-generated custom
targets because the output is SYMBOLIC (to always run) and the generated
file is a byproduct (for restat so dependents do not run unnecessarily).

The two use cases conflict because Ninja does not support per-output
restat.  Favor restat whenever byproducts are present because it is
required for byproducts to work correctly.  In use cases where we want
an always-run chain we simply will not be able to also use byproducts.