nir: fix ir_binop_gequal glsl_to_nir conversion

ir_binop_gequal needs to be converted to nir_op_sge when native integers
are not supported in the driver.
Otherwise it becomes no different than ir_binop_less after the
conversion.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/compiler/glsl/glsl_to_nir.cpp

@@ -1832,7 +1832,7 @@ nir_visitor::visit(ir_expression *ir)
          else
             result = nir_uge(&b, srcs[0], srcs[1]);
       } else {
-         result = nir_slt(&b, srcs[0], srcs[1]);
+         result = nir_sge(&b, srcs[0], srcs[1]);
       }
       break;
    case ir_binop_equal: