Avoid using R0 and R1.

src/Appli/Fappli_IEEE.v

src/Core/Fcore_FLT.v

src/Core/Fcore_FTZ.v

src/Core/Fcore_Raux.v

src/Core/Fcore_float_prop.v

src/Core/Fcore_generic_fmt.v

src/Core/Fcore_ulp.v

src/Prop/Fprop_div_sqrt_error.v

src/Prop/Fprop_plus_error.v

src/Prop/Fprop_relative.v