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 for RCC files which are generated.

The cmake_autogen build step is implemented as a PRE_BUILD step
of the target currently if possible, rather than a standalone
custom target.  This is to keep the number of (synthesized)
custom targets that appear in the UI low, but in some cases
it is necessary to fall back to a full custom target.

Fall back to a full custom target for the VS builds if autorcc
is used.

1 files changed, 5 insertions, 0 deletions

diff --git a/Tests/QtAutogen/autorcc_depends/test_res1.cpp b/Tests/QtAutogen/autorcc_depends/test_res1.cpp
new file mode 100644
index 0000000..766b775
--- /dev/null
+++ b/Tests/QtAutogen/autorcc_depends/test_res1.cpp
@@ -0,0 +1,5 @@
+
+int main()
+{
+  return 0;
+}