nir: add array length field

This will simplify things somewhat in clone.

Signed-off-by: Rob Clark <robclark@freedesktop.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>

src/glsl/nir/glsl_to_nir.cpp

@@ -240,6 +240,8 @@ constant_copy(ir_constant *ir, void *mem_ctx)
 
    unsigned total_elems = ir->type->components();
    unsigned i;
+
+   ret->num_elements = 0;
    switch (ir->type->base_type) {
    case GLSL_TYPE_UINT:
       for (i = 0; i < total_elems; i++)
@@ -264,6 +266,8 @@ constant_copy(ir_constant *ir, void *mem_ctx)
    case GLSL_TYPE_STRUCT:
       ret->elements = ralloc_array(mem_ctx, nir_constant *,
                                    ir->type->length);
+      ret->num_elements = ir->type->length;
+
       i = 0;
       foreach_in_list(ir_constant, field, &ir->components) {
          ret->elements[i] = constant_copy(field, mem_ctx);
@@ -274,6 +278,7 @@ constant_copy(ir_constant *ir, void *mem_ctx)
    case GLSL_TYPE_ARRAY:
       ret->elements = ralloc_array(mem_ctx, nir_constant *,
                                    ir->type->length);
+      ret->num_elements = ir->type->length;
 
       for (i = 0; i < ir->type->length; i++)
          ret->elements[i] = constant_copy(ir->array_elements[i], mem_ctx);

src/glsl/nir/nir.h

@@ -111,6 +111,11 @@ typedef struct nir_constant {
     */
    union nir_constant_data value;
 
+   /* we could get this from the var->type but makes clone *much* easier to
+    * not have to care about the type.
+    */
+   unsigned num_elements;
+
    /* Array elements / Structure Fields */
    struct nir_constant **elements;
 } nir_constant;