Tests are running without -O since f377f69fec28013c79db4efe12bbb9d48987fb2c because some warnings (about
yylval not being initialized) show only when GCC is given -O2. The
previous patch fixes the warnings. Run the test suite with compiler
options unmodified.
* tests/atlocal.in (O0CFLAGS, O0CXXFLAGS): Remove, use CFLAGS and
CXXFLAGS.