[lex.ext] Fully-qualify std::size_t in example.
[gram] Rebuild grammar after eb18f34d.
[temp.names] Add missing comma.
[bitset.cons] Fix typo and surrounding inconsistencies.

Fixes #294.
[basic.def.odr] Clarify the meaning of the set of potential results of
an expression and how that relates to odr-use.
[basic.def.odr] Fix example to perform the lvalue-to-rvalue conversion
outside the conditional expression, as intended.