Avoid using "typeid" as a parameter name in header files, since that
is a C++ keyword.  These cases were introduced recently, in 04fe805a
and 586b98fd.

Since I'm an incurable neatnik, also rename these parameters in the
underlying function definitions.  That's not really necessary per
project rules, but I don't like function declarations that don't
quite agree with the underlying definitions.

Per src/tools/pginclude/cpluspluscheck.