Verify a touchpad is present before polling it for input. Without this
check the Debug log is spammed with the message "error: Parameter
'touchpad' is invalid" if you have a controller without a touchpad.
One would think every touchpad supports at least 1 finger, but in case
there's some weird edge case check the finger count to be sure.
This is an Android continuation of bc95c00. We now call
InputDetector::Update immediately after receiving an input event from
Android instead of periodically calling it in a sleep loop. This
improves detection of very short inputs, which are especially likely to
occur for volume buttons on phones (or at least on my phone) if you
don't intentionally keep them held down.
In NandPaths.cpp, the `std::initializer_list<char>` of illegal characters has been turned into a `char[]` (similar to the one in GameList.cpp).
The reverse iteration in ResourcePack.cpp seemed to provide no benefits, and doing without it it seemed to have no ill effects.
In WiimoteReal.cpp, JitRegCache.cpp, lambda predicates were replaced by pointers to member functions because ranges algorithms are able invoke those.
In ConvertDialog.cpp, the `std::mem_fn` helper was removed because ranges algorithms are able to handle pointers to member functions as predicates.
In DITSpecification.cpp, MaterialAsset.cpp, and ShaderAsset.cpp, lambda predicates were replaced by pointers to member functions because ranges algorithms are able invoke those.
In NetPlayClient.cpp, the non-trivial `NetPlay::Player` elements were being passed by value in `NetPlayClient::DoAllPlayersHaveGame()`. This has been fixed.
In WIABlob.cpp, the second example's predicate was returning the `std::optional` by value instead of implicitly converting it to a bool. This has been fixed.
In DSPCore.cpp, there were two `std::fill` uses that could be simplified using `std::fill_n`. Due to their proximity with other `std::fill` algorithms being modernized with ranges, I chose to make these examples into the rare `std::ranges::fill_n`.
With 12 uses of `JoinStrings` in the codebase vs 36 uses of `fmt::join`, fmtlib's range adapter for string concatenation with delimiters is clearly the preferred option.
