Tests: Add case for warning when AUTOMOC/UIC/RCC gets disabled

Tests/RunCMake/Autogen/CMakeLists.txt

+cmake_minimum_required(VERSION 3.13)
+project(${RunCMake_TEST} NONE)
+include(${RunCMake_TEST}.cmake)

Tests/RunCMake/Autogen/NoQt-stderr.txt

+^CMake Warning \(dev\) in CMakeLists.txt:
+  AUTOGEN: No valid Qt version found for target main.  AUTOMOC, AUTOUIC,
+  AUTORCC disabled.  Consider adding:
+
+    find_package\(Qt5 COMPONENTS Widgets\)
+
+  to your CMakeLists.txt file.
+This warning is for project developers.  Use -Wno-dev to suppress it.

Tests/RunCMake/Autogen/NoQt.cmake

+enable_language(CXX)
+
+add_executable(main empty.cpp)
+set_property(TARGET main PROPERTY AUTOMOC 1)
+set_property(TARGET main PROPERTY AUTORCC 1)
+set_property(TARGET main PROPERTY AUTOUIC 1)

Tests/RunCMake/Autogen/RunCMakeTest.cmake

+include(RunCMake)
+
+run_cmake(NoQt)

Tests/RunCMake/CMakeLists.txt

@@ -142,6 +142,7 @@ if(NOT CMake_TEST_EXTERNAL_CMAKE)
 endif()
 
 add_RunCMake_test(AndroidTestUtilities)
+add_RunCMake_test(Autogen)
 add_RunCMake_test(BuildDepends)
 if(UNIX AND "${CMAKE_GENERATOR}" MATCHES "Unix Makefiles|Ninja")
   add_RunCMake_test(Byproducts)