nir: nir_shader_compiler_options: drop native_integers

Driver which do not support native integers should use a lowering
pass to go from integers to floats.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/compiler/nir/nir.h

@@ -2300,12 +2300,6 @@ typedef struct nir_shader_compiler_options {
    bool lower_all_io_to_temps;
    bool lower_all_io_to_elements;
 
-   /**
-    * Does the driver support real 32-bit integers?  (Otherwise, integers
-    * are simulated by floats.)
-    */
-   bool native_integers;
-
    /* Indicates that the driver only has zero-based vertex id */
    bool vertex_id_zero_based;