glsl/opt_algebraic: Drop pow-recognizer.

NIR handles pow recognizing, too.  No change on freedreno shader-db.

Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21475>

src/compiler/glsl/opt_algebraic.cpp

@@ -327,25 +327,6 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
       }
       break;
 
-   case ir_unop_exp2:
-      if (op_expr[0] == NULL)
-	 break;
-
-      if (op_expr[0]->operation == ir_binop_mul) {
-         for (int log2_pos = 0; log2_pos < 2; log2_pos++) {
-            ir_expression *log2_expr =
-               op_expr[0]->operands[log2_pos]->as_expression();
-
-            if (log2_expr && log2_expr->operation == ir_unop_log2) {
-               return new(mem_ctx) ir_expression(ir_binop_pow,
-                                                 ir->type,
-                                                 log2_expr->operands[0],
-                                                 op_expr[0]->operands[1 - log2_pos]);
-            }
-         }
-      }
-      break;
-
    case ir_unop_f2i:
    case ir_unop_f2u:
       if (op_expr[0] && op_expr[0]->operation == ir_unop_trunc) {