Clang: Add clang query

Clang query is mechanism to use AST matcher to search for code. Think
about regular expression but in the context of AST. So you get a semantic
search tool for C++.

Change-Id: I72e882c5b53a0c52f352a3664847c4c3e4f6fc2e
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/cpptools/cppprojectfile.cpp

@@ -34,11 +34,6 @@
 
 namespace CppTools {
 
-ProjectFile::ProjectFile()
-    : kind(CHeader)
-{
-}
-
 ProjectFile::ProjectFile(const QString &file, Kind kind)
     : path(file)
     , kind(kind)