C++: code completion for lambda calls

support for lambdas, e.g.:
struct S { int bar; };
[]() { return new S; } ()->bar;
[] { return new S; } ()->bar;
[]() ->S* { return new S(); } ()->bar;
[]() throw() { return new S(); } ()->bar;
[]() throw()->S* { return new S(); } ()->bar;

Task-number: QTCREATORBUG-9523
Change-Id: I43fbf6f0ee0bb11411c53c984df75ef33a276466
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>