ClangPchManager: Add build dependencies to include collector

It's a first step but we have to refactor the interface later.

Task-number: QTCREATORBUG-21379
Change-Id: Idda666bcaec950203f001c993c54a926779527e0
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/tools/clangrefactoringbackend/source/clangtool.cpp

@@ -25,6 +25,8 @@
 
 #include "clangtool.h"
 
+#include <iostream>
+
 namespace ClangBackEnd {
 
 namespace {