Implement type inference for PropertySet.

pkg/front_end/testcases/inference/property_set.dart.outline.expect

Index: pkg/front_end/testcases/inference/property_set.dart.outline.expect
diff --git a/pkg/front_end/testcases/inference/property_set.dart.outline.expect b/pkg/front_end/testcases/inference/property_set.dart.outline.expect
new file mode 100644
index 0000000000000000000000000000000000000000..a72885144c2ef02720b6f101383c940b83fd7078
--- /dev/null
+++ b/pkg/front_end/testcases/inference/property_set.dart.outline.expect
@@ -0,0 +1,13 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+class A<T extends core::Object> extends core::Object {
+  field core::List<self::A::T> x;
+  constructor •() → void
+    ;
+  set y(core::List<self::A::T> value) → void
+    ;
+}
+static method main() → dynamic
+  ;