QtAutogen: Extract a GetRccExecutable method.
QtAutogen: Expand rccfiles into a vector early in the autogen process.

This can be re-used as a vector.
QtAutogen: Regenerate qrc files if their input changes (#15074)

Get dependencies from the output of ``rcc --list`` if using
Qt 5. Otherwise process the file in the same way as the
qt4_add_resources macro.

This does not work with the Ninja generator, and it does not
work for RCC files which are generated.
Merge topic 'autorcc-depends' into next

fc4e9c64 QtAutogen: Regenerate qrc files if their input changes (#15074)
cace5a81 QtAutogen: Expand rccfiles into a vector early in the autogen process.
00095adf QtAutogen: Extract a GetRccExecutable method.