CppTools: Add target type information to project part

Let project managers store information whether a project part
belongs to an executable or a library and use this information
inside the AutoTest plugin.
This information will help to determine which targets are
relevant for the execution of tests.

Change-Id: I93b42797bf55225425398dc83aecea3c99eea290
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/cpptools/cpprawprojectpart.cpp

@@ -133,4 +133,9 @@ void RawProjectPart::setFlagsForCxx(const RawProjectPartFlags &flags)
     flagsForCxx = flags;
 }
 
+void RawProjectPart::setBuildTargetType(ProjectPart::BuildTargetType type)
+{
+    buildTargetType = type;
+}
+
 } // namespace CppTools