If Qt is configured with ccache feature pass that along to GN

This will set the cc_wrapper to ccache when running GN, which in turn
will prefix all compiler calls with ccache. This allows a nice way of
using ccache and icecream on macOS.

Change-Id: I19ca1261aa8ebc4aaf7f8c34b3cb363baa29de01
Reviewed-by: Allan Sandfeld Jensen <[email protected]>

Author: alcroito

src/core/config/common.pri

@@ -114,3 +114,7 @@ qtConfig(webengine-kerberos) {
 }
 
 !msvc: gn_args += enable_iterator_debugging=false
+
+ccache {
+    gn_args += cc_wrapper=\"ccache\"
+}