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/libs/clangbackendipc/refactoringclientinterface.h

@@ -32,6 +32,7 @@
 namespace ClangBackEnd {
 
 class SourceLocationsForRenamingMessage;
+class SourceRangesAndDiagnosticsForQueryMessage;
 class SourceLocationsContainer;
 
 class CMBIPC_EXPORT RefactoringClientInterface : public IpcClientInterface
@@ -45,6 +46,7 @@ public:
 
     virtual void alive() = 0;
     virtual void sourceLocationsForRenamingMessage(SourceLocationsForRenamingMessage &&message) = 0;
+    virtual void sourceRangesAndDiagnosticsForQueryMessage(SourceRangesAndDiagnosticsForQueryMessage &&message) = 0;
 
     virtual void setLocalRenamingCallback(RenameCallback &&localRenamingCallback) = 0;
 };