[Bug c++/82899] *this in constructors could not alias with reference input parameters of the same type

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82899

--- Comment #19 from Marc Glisse <glisse at gcc dot gnu.org> ---
(In reply to rguenther@suse.de from comment #18)
> I suppose this changes debug information?

Yes. Probably not so bad, but indeed better if we can avoid it.

> I think adjusting the only user in tree-ssa-structalias.c is better.

I was trying to avoid adding more language-specific stuff to the middle-end,
especially since I wasn't sure if constructors were also used by other
languages, but I see the bit is now called cxx_constructor and tested with
DECL_CXX_CONSTRUCTOR_P so it should be safe.