CXXFeatures: 2 more add expected features for XL
CXXFeatures: show full outputs for unknown compilers
CXXFeatures: BCC seems to support long long only since 5.60
Merge topic 'cxx11' into next

7662bef CXXFeatures: BCC seems to support long long only since 5.60
214099f CXXFeatures: show full outputs for unknown compilers
3adf4da CXXFeatures: 2 more add expected features for XL