Implement type inference for "not" expressions.

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 70eb984e2929dd2541956ff440634ae00c44856f..f9f15645dc5352ea68fb2d165696837252954824 100644
--- a/pkg/front_end/test/fasta/strong.status
+++ b/pkg/front_end/test/fasta/strong.status
@@ -61,8 +61,6 @@ inference/downwards_inference_on_function_of_t_using_the_t: Fail
 inference/future_then_explicit_future: Fail
 inference/generic_functions_return_typedef: Fail
 inference/generic_methods_infer_js_builtin: Fail
-inference/infer_binary_double_double: Fail
-inference/infer_binary_double_int: Fail
 inference/infer_binary_int_double: Fail
 inference/infer_binary_int_int: Fail
 inference/infer_consts_transitively_2: Fail
@@ -75,7 +73,6 @@ inference/infer_from_variables_in_cycle_libs_when_flag_is_on: Fail
 inference/infer_from_variables_in_cycle_libs_when_flag_is_on2: Fail
 inference/infer_from_variables_in_non_cycle_imports_with_flag: Fail
 inference/infer_from_variables_in_non_cycle_imports_with_flag2: Fail
-inference/infer_prefix_expression: Fail
 inference/infer_statics_transitively: Fail
 inference/infer_statics_transitively3: Fail
 inference/infer_statics_transitively_a: Fail