i965/gen9: Don't do fast clears when GL_FRAMEBUFFER_SRGB is enabled
i965/gen9: Don't do fast clears when GL_FRAMEBUFFER_SRGB is enabled

When GL_FRAMEBUFFER_SRGB is enabled any single-sampled renderbuffers
are resolved in intel_update_state because the hardware can't cope
with fast clears on SRGB buffers. In that case it's pointless to do a
fast clear because it will just be immediately resolved.

Reviewed-by: Topi Pohjolainen <749697f19798b7f640b17221fd283b903825f071@intel.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler