Add type inference for assert statements.

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

Index: pkg/front_end/testcases/inference/assert.dart.outline.expect
diff --git a/pkg/front_end/testcases/inference/assert.dart.outline.expect b/pkg/front_end/testcases/inference/assert.dart.outline.expect
new file mode 100644
index 0000000000000000000000000000000000000000..ac49c9eafa9da7fa70885d0ab8d3acbcb29c9439
--- /dev/null
+++ b/pkg/front_end/testcases/inference/assert.dart.outline.expect
@@ -0,0 +1,10 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+static method f<T extends core::Object>() → self::f::T
+  ;
+static method test() → void
+  ;
+static method main() → dynamic
+  ;