Prevent this by modifying CFLAGS and CXXFLAGS.
Upmerge from 5.0, modified according to the different spec file structure.
support-files/mysql.spec.sh:
Bug #40546 Debug server in RPM is built with compiler optimization
Modify CFLAGS and CXXFLAGS for the duration of the debug server build
(implemented by doing it in a subshell)
so that they do not contain any optimization flag.
Play it safe and prepare for both gcc and icc.