[Mesa-dev] Killing broken configure toggles and fixing autotools gl.pc

[Emil Velikov]

Hi all,

While fixing a gl.pc + glvnd bug (well sort of), I noticed the 
following:

With GLVND, we started abusing GL_LIB a lot more. Currently autotools 
can do a) custom libGL name, b) mangled GL and 
c) GLVND.

Turns out that a + b was broken, since b was introduced. There is very 
limited reason why a would exist and since it's broken I'm just nuking 
it.

OSMesa was in the same a/b shape so it gets the same axe.

Note: now configure will error out if anyone explicitly touches the 
toggles.
Note: the whole series should be applicable for stable - I will check 
the exact commits/branches and annotate accordingly

WARNINING: The series isn't even build tested, but I'm sending it out 
for feedback since the topic be a bit ...

Any feedback, even a general ACK will be appreciated.
Emil

Cc: Brian Paul <brianp at vmware.com>
Cc: Dylan Baker <dylan at pnwbakers.com>