CXXFeatures: update list of expected features

Also fix a warning about an unreferenced variable in the testcase program.
CXXFeatures: add flags used by Intel compiler on Windows
CXXFeatures: wrap test-and-set for compiler flag in function
Merge topic 'cxx11' into next

3085efc CXXFeatures: wrap test-and-set for compiler flag in function
e030537 CXXFeatures: add flags used by Intel compiler on Windows
96250fd CXXFeatures: update list of expected features