Implement type inference of method invocations in Fasta.

pkg/front_end/testcases/inference/inferred_type_custom_unary_op.dart.strong.expect

Index: pkg/front_end/testcases/inference/inferred_type_custom_unary_op.dart.strong.expect
diff --git a/pkg/front_end/testcases/inference/inferred_type_custom_unary_op.dart.strong.expect b/pkg/front_end/testcases/inference/inferred_type_custom_unary_op.dart.strong.expect
new file mode 100644
index 0000000000000000000000000000000000000000..618659ec5e52f5ad6cf652d7af7e9c2beb355152
--- /dev/null
+++ b/pkg/front_end/testcases/inference/inferred_type_custom_unary_op.dart.strong.expect
@@ -0,0 +1,17 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  constructor •() → void
+    : super core::Object::•()
+    ;
+  operator unary-() → core::bool
+    return true;
+}
+static field self::C c = new self::C::•();
+static field core::bool x = self::c.unary-();
+static method main() → dynamic {
+  self::c;
+  self::x;
+}