[PATCH] Fix write to uninitialized bytes for XCB event

[Pavel Sanda]

On Wed, Feb 19, 2020 at 06:13:08PM +0100, Pavel Sanda wrote:
> > We are requiring C++11 these days, right?
> 
> Can't remember, notions of gcc 4.7 in INSTALL is not strongly indicative of that ;)
> Need to check whether one of my antique system still compiles with 4.7 or 4.8,
> maybe we can bump to 4.8.

So the oldest distro on which I regularly compile lyx master has gcc 4.8.
Because I suspect no one around is using even older config we can't really
guarantee 4.7 (stand up if I am wrong) so we should change INSTALL instructions
to 4.8 and freely use the suggested alignas(32).

Pavel