class_linker: Add support for resolving method types.

- Add a new fixed size dex cache array for resolved method types.
  The size of this array is set to 1024.
- Also introduces a new runtime flag that controls this feature.

Test: make test-art-host
Bug: 30550796

Change-Id: I147b33398d71ee21f2e91b418d3700d4630801ff
diff --git a/runtime/parsed_options.cc b/runtime/parsed_options.cc
index 4f70b04..f937ca7 100644
--- a/runtime/parsed_options.cc
+++ b/runtime/parsed_options.cc
@@ -761,6 +761,8 @@
                        "(Enable new and experimental agent support)\n");
   UsageMessage(stream, "  -Xexperimental:agents"
                        "(Enable new and experimental agent support)\n");
+  UsageMessage(stream, "  -Xexperimental:method-handles"
+                       "(Enable new and experimental method handles support)\n");
   UsageMessage(stream, "\n");
 
   UsageMessage(stream, "The following previously supported Dalvik options are ignored:\n");