CFG: Add CFGElement for automatic variables that leave the scope
This mimics the implementation for the implicit destructors. The
generation of this scope leaving elements is hidden behind
a flag to the CFGBuilder, thus it should not affect existing code.
Currently, I'm missing a test (it's implicitly tested by the clang-tidy
lifetime checker that I'm proposing).
I though about a test using debug.DumpCFG, but then I would
have to add an option to StaticAnalyzer/Core/AnalyzerOptions
to enable the scope leaving CFGElement,
which would only be useful to that particular test.
Any other ideas how I could make a test for this feature?
Reviewers: krememek, jordan_rose
Differential Revision: http://reviews.llvm.org/D15031