Move redundant `auto_cast` error from `-vet` to `-vet-extra`

src/check_expr.cpp

@@ -429,6 +429,7 @@ bool find_or_generate_polymorphic_procedure(CheckerContext *old_c, Entity *base_
 	if (poly_proc_data) {
 		poly_proc_data->gen_entity = entity;
 		poly_proc_data->proc_info  = proc_info;
+		entity->Procedure.generated_from_polymorphic = proc_info->generated_from_polymorphic;
 	}
 
 	// NOTE(bill): Check the newly generated procedure body
@@ -7965,10 +7966,8 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			Type *type = type_of_expr(ac->expr);
 			check_cast(c, o, type_hint);
 			if (is_type_typed(type) && are_types_identical(type, type_hint)) {
-				if (build_context.vet) {
+				if (build_context.vet_extra) {
 					error(node, "Redundant 'auto_cast' applied to expression");
-				} else {
-					// warning(node, "Redundant 'auto_cast' applied to expression");
 				}
 			}
 

src/entity.cpp

@@ -183,6 +183,7 @@ struct Entity {
 			DeferredProcedure deferred_procedure;
 			bool    is_foreign;
 			bool    is_export;
+			bool    generated_from_polymorphic;
 			ProcedureOptimizationMode optimization_mode;
 		} Procedure;
 		struct {

src/llvm_backend_expr.cpp

@@ -1204,6 +1204,17 @@ lbValue lb_emit_conv(lbProcedure *p, lbValue value, Type *t) {
 			}
 			return lb_emit_conv(p, res, t);
 		}
+		
+		if (is_type_integer_128bit(dst)) {
+			auto args = array_make<lbValue>(temporary_allocator(), 1);
+			args[0] = value;
+			char const *call = "fixunsdfdi";
+			if (is_type_unsigned(dst)) {
+				call = "fixunsdfti";
+			}
+			lbValue res_i128 = lb_emit_runtime_call(p, call, args);
+			return lb_emit_conv(p, res_i128, t);
+		}
 
 		lbValue res = {};
 		res.type = t;