ASTImporter causes assertion in full mode

Hi @clang,

the second assertion in DeclContext::addHiddenDecl fires, if I import a function in a namespace with two function paramters in ASTImporter's full mode.
I'm not that familiar with the ASTImporter but it seems, that the call to ImportDeclParts in ASTNodeImporter::VisitFunctionDecl imports all decls of the namespace including the currently processed function. Later on the function imports its parameters and there the assertion happens because the parameters are already imported.
Perhaps someone should look at this. I got it solved here by switching to minimal import.

Best regards
Olaf Krzikalla