QRegExp include cleanup

This patch adds the missing include statements for QRegExp.

Change-Id: Ibb03b929940adb84ae190b5090cb6b88653cc14c
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/cpptools/builtinindexingsupport.cpp

@@ -46,6 +46,7 @@
 #include <QCoreApplication>
 #include <QDir>
 #include <QElapsedTimer>
+#include <QRegExp>
 
 using namespace CppTools;
 using namespace CppTools::Internal;

src/plugins/cpptools/cppcurrentdocumentfilter.cpp

@@ -31,6 +31,7 @@
 #include <coreplugin/editormanager/editormanager.h>
 #include <coreplugin/editormanager/ieditor.h>
 
+#include <QRegExp>
 #include <QStringMatcher>
 
 using namespace CppTools::Internal;

src/plugins/cpptools/cpplocatorfilter.cpp

@@ -28,6 +28,7 @@
 
 #include <coreplugin/editormanager/editormanager.h>
 
+#include <QRegExp>
 #include <QStringMatcher>
 
 #include <algorithm>