softpipe: don't clamp reference value for shadow comparison for float formats
softpipe: don't clamp reference value for shadow comparison for float formats

Clamping is only done for fixed-point formats as part of conversion to
texture format.

Reviewed-by: Zack Rusin <6ab0df0692bc027e828ec9e4e9fbe8fa1a7842a8@vmware.com>

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