Fix exporting of Core tools

It should happen after qmake is built, to make sure that the target is
made global, otherwise when cross-building qtbase in another build tree,
the configuration phase will fail due to not finding qmake.

qmake was accidentally exported before if you configured qtbase twice,
because the tool was kept around in a cache variable, the second
configuration actually recreated the CoreToolsConfig.cmake file to
contain qmake as well.

Change-Id: I6941e83f7d6bd03c56de120fba1d18e50c4af0e4
Reviewed-by: Qt CMake Build Bot
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

CMakeLists.txt

@@ -55,6 +55,9 @@ if (QT_WILL_BUILD_TOOLS)
     add_subdirectory(qmake)
 endif()
 
+# Need to build qmake and other Core tools before exporting them.
+qt_export_tools(Core)
+
 # As long as we use the mkspecs (for qplatformdefs.h), we need to always
 # install it, especially when cross-compiling.
 set(mkspecs_install_dir "${INSTALL_DATADIR}")

src/CMakeLists.txt

@@ -26,9 +26,6 @@ if (QT_FEATURE_xml)
 endif()
 add_subdirectory(tools)
 
-# Need to build qmake and other Core tools before exporting them.
-qt_export_tools(Core)
-
 if (QT_FEATURE_dbus)
     add_subdirectory(dbus)
 endif()