NB CA-22 CH-5 __func__ in a lambda body

As directed by CWG Motion 1 from 2014-Isaquah.

Also fixes CWG1772.
NB CA-14 Out-of-lifetime lvalue-to-rvalue conversion

As directed by CWG Motion 1 from 2014-Isaquah.

Also fixes CWG1773.
Fix example in last commit (NB CA-14 Out-of-lifetime lvalue-to-rvalue conversion CWG1773)
NB CA-26 Undefined behavior of line splice in raw string literal

As directed by CWG Motion 1 from 2014-Isaquah.

Also fixes CWG1775.