Fix type inference of PropertySet when the receiver is a generic class.

pkg/front_end/test/fasta/strong.status

Index: pkg/front_end/test/fasta/strong.status
diff --git a/pkg/front_end/test/fasta/strong.status b/pkg/front_end/test/fasta/strong.status
index ca8c14f738a90eaa89d49c06d6e4aa6ece3a8380..2dca7441fd91f01bead96cdc7a60f5cf853c15c1 100644
--- a/pkg/front_end/test/fasta/strong.status
+++ b/pkg/front_end/test/fasta/strong.status
@@ -63,8 +63,6 @@ inference/infer_types_on_loop_indices_for_loop_with_inference: Fail
 inference/infer_use_of_void: Fail
 inference/list_literals_can_infer_null_top_level: Fail
 inference/map_literals_can_infer_null_top_level: Fail
-inference/property_set: Fail
-inference/property_set_bad_setter: Crash
 inference/reference_to_typedef: Fail
 inference/refine_binary_expression_type_type_parameter_t_double: Fail
 inference/refine_binary_expression_type_type_parameter_t_int: Fail