ProjectExplorer: Introduce SeparateDebugInfoAspect

... and use it in the qbs build configuration.

Change-Id: Ie9002e5c43d1d43c81dc30a1fcbb29a5a1a25705
Reviewed-by: hjk <hjk@qt.io>

src/plugins/projectexplorer/buildaspects.cpp

@@ -27,4 +27,10 @@
 
 namespace ProjectExplorer {
 
+SeparateDebugInfoAspect::SeparateDebugInfoAspect()
+{
+    setDisplayName(tr("Separate Debug Info"));
+    setSettingsKey("SeparateDebugInfo");
+}
+
 } // namespace ProjectExplorer