RFC - Remove support for PCH post 4.8

[Eric Botcazou]

> I admit that I'm partly fishing here, but my proposal is based on the
> following:
> 
> * The implementation of PCH in GCC is atrocious and hard to maintain.
> * The next C++ standard is likely to define modules
> (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3347.pdf)
> * The user-base for PCH is negligibly small (here's where I'm mostly
> guessing). * PCH is absolutely useless for C.
> 
> Removing PCH will give us more implementation freedom for the memory
> management project
> (http://gcc.gnu.org/wiki/cxx-conversion/gc-alternatives).

One of the arguments put forward to advocate the transition to C++ was the 
competition.  Where do the other compilers stand when it comes to PCHs?

-- 
Eric Botcazou