nvfx: fix/workaround nv3x hwtnl issues
nvfx: fix/workaround nv3x hwtnl issues

This patch re-emits the viewport state on framebuffer or rasterizer
change.

This seems to be necessary on nv3x, but the reason is not fully
understood.

It is quite likely that this isn't really the correct fix, but seems
to work, and makes nv3x much better.

bkaradzic/glsl-optimizer,KTXSoftware/glsl2agal,djreep81/glsl-optimizer,adobe/glsl2agal,mapbox/glsl-optimizer,KTXSoftware/glsl2agal,metora/MesaGLSLCompiler,zz85/glsl-optimizer,tokyovigilante/glsl-optimizer,mcanthony/glsl-optimizer,djreep81/glsl-optimizer,adobe/glsl2agal,adobe/glsl2agal,benaadams/glsl-optimizer,dellis1972/glsl-optimizer,jbarczak/glsl-optimizer,mapbox/glsl-optimizer,tokyovigilante/glsl-optimizer,wolf96/glsl-optimizer,KTXSoftware/glsl2agal,mapbox/glsl-optimizer,djreep81/glsl-optimizer,zeux/glsl-optimizer,metora/MesaGLSLCompiler,zeux/glsl-optimizer,jbarczak/glsl-optimizer,bkaradzic/glsl-optimizer,bkaradzic/glsl-optimizer,zz85/glsl-optimizer,mcanthony/glsl-optimizer,adobe/glsl2agal,zeux/glsl-optimizer,benaadams/glsl-optimizer,zz85/glsl-optimizer,KTXSoftware/glsl2agal,wolf96/glsl-optimizer,zeux/glsl-optimizer,metora/MesaGLSLCompiler,jbarczak/glsl-optimizer,dellis1972/glsl-optimizer,tokyovigilante/glsl-optimizer,KTXSoftware/glsl2agal,benaadams/glsl-optimizer,bkaradzic/glsl-optimizer,jbarczak/glsl-optimizer,jbarczak/glsl-optimizer,djreep81/glsl-optimizer,tokyovigilante/glsl-optimizer,zeux/glsl-optimizer,mcanthony/glsl-optimizer,bkaradzic/glsl-optimizer,benaadams/glsl-optimizer,dellis1972/glsl-optimizer,zz85/glsl-optimizer,wolf96/glsl-optimizer,tokyovigilante/glsl-optimizer,mapbox/glsl-optimizer,wolf96/glsl-optimizer,wolf96/glsl-optimizer,adobe/glsl2agal,mcanthony/glsl-optimizer,zz85/glsl-optimizer,mcanthony/glsl-optimizer,benaadams/glsl-optimizer,mapbox/glsl-optimizer,zz85/glsl-optimizer,dellis1972/glsl-optimizer,benaadams/glsl-optimizer,djreep81/glsl-optimizer,dellis1972/glsl-optimizer