We had to force-include Char16.h to simulate char16_t on older MSVC versions.
But it is no longer the case. We should not rebuild the world whenever we
touch this file.
MozReview-Commit-ID: 1XY7tQD8LoK
In order to properly disable template functions with `std::enable_if` we need
to use the resulting type. This only works if we use a dependent type in the
template params, hence the need to shadow the `T` param.
Proper usage is now of the form:
template<typename Q = T, typename EnableIfChar = CharOnlyT<Q>>
Foo();
This removes the double-include macro hackery that we use to define two
separate string types (nsAString and nsACString) in favor of a templated
solution.
Annotations for Valgrind and the JS hazard analysis are updated as well as
the rust binding generations for string code.
