clover: compile all sources with c++11
clover: compile all sources with c++11

Later we can remove the compat code

Reviewed-by: Francisco Jerez <5906ff32bdd9fd8db196f6ba5ad3afd6f9257ea5@riseup.net>
Reviewed-by: Tom Stellard <85590917cb30a670bf23f5b4273617f8815d1e87@amd.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler