Possible regression with GLX+Xvfb after 5f5bbbe?

[Raphael Kubo da Costa]

Hey there, everyone.

I've recently had to test some code which relies on GLX using Xvfb on
xorg-server 1.13.0, but it looks like it is not loaded anymore after
commit 5f5bbbe543f65c48ecbb5cce80116a86ca3fbe86.

It turns out that this commit removed a duplicate code path in
miinitext.c which was used by Xvfb and was responsible for calling
GlxExtensionInit(). Right now, even passing `+extension GLX' does not
help, since the contents of ExtensionToggleList are not read in
InitExtensions().

Furthermore, commit aad428b8e21c77397c623b78706eb64b1fea77c9, makes
attempts to call GlxExtensionInit() in miinitext.c fail when linking the
unit tests.

Before working on a patch (or hoping someone else does that :-), I'd
like to clarify whether this side-effect was not really intentional.