Tests: Teach RunCMake to ignore Intel -Wdebug-disables-optimization warnings

The Intel compiler may warn:

    icpx: warning: Note that use of '-g' without any optimization-level
    option will turn off most compiler optimizations similar to use of
    '-O0' [-Wdebug-disables-optimization]

Teach RunCMake to drop such incidental lines before matching against
expected output.