[C++ Patch] Add IS_DIRECT_INITIALIZER?

[Paolo Carlini]

Hi,

I was having a look to a couple of issues in this area, and wondered if 
we want to do something like the below? In case, I would also go with 
the first init.c hunk and the mangle.c hunk, I don't think the 
additional check can hurt?!?

Thanks,
Paolo.

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