Disable two ADOL-C tests in release configuration

It turns out that some optimizing compilers (gcc-7 onwards) are very
happy in happily optimizing away in case of undefined behavior (that we
are apparently encountering). Let's just disable these tests in release
configuration.

diff --git a/tests/adolc/helper_scalar_failure_04.output b/tests/adolc/helper_scalar_failure_04.debug.output
similarity index 100%
rename from tests/adolc/helper_scalar_failure_04.output
rename to tests/adolc/helper_scalar_failure_04.debug.output

diff --git a/tests/adolc/helper_tape_index_01.output b/tests/adolc/helper_tape_index_01.debug.output
similarity index 100%
rename from tests/adolc/helper_tape_index_01.output
rename to tests/adolc/helper_tape_index_01.debug.output