In a previous commit[1], diagnostic pragmas were used to avoid this
warning. However, the incorrect warning flag was indicated, leaving the
warning in place. -Wdeprecated is for deprecated features while
-Wdeprecated-declarations for deprecated functions, variables, and
types[2].
[1] c408461983
[2] https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html