CWG1850 Differences between definition context and point of instantiation
	- fixed missing tcode around "const".
CWG1571 cv-qualification for indirect reference binding via conversion function
    - fixed typo in original commit (changed T1 to T2)
CWG1780 Explicit instantiation/specialization of generic lambda operator()
    - fixed missing tcode around "friend".
CWG591 When a dependent base class is the current instantiation
    - add tcode around code inside example's comment.