Precompilation: Generate instance calls as IC calls that can switch to Megamoprhic calls.

runtime/vm/code_patcher.h

Index: runtime/vm/code_patcher.h
diff --git a/runtime/vm/code_patcher.h b/runtime/vm/code_patcher.h
index dc2716856a9d62b3b0bfd065ee904b7b083a37df..ebcdeaaed666992007a38d06011508620a39fc6d 100644
--- a/runtime/vm/code_patcher.h
+++ b/runtime/vm/code_patcher.h
@@ -74,6 +74,12 @@ class CodePatcher : public AllStatic {
                                      const Code& code,
                                      const Code& new_target);
 
+  static void PatchSwitchableCallAt(uword return_address,
+                                    const Code& code,
+                                    const ICData& ic_data,
+                                    const MegamorphicCache& new_cache,
+                                    const Code& lookup_stub);
+
   static RawCode* GetNativeCallAt(uword return_address,
                                   const Code& code,
                                   NativeFunction* target);