6894206: JVM needs a way to traverse method handle structures

We need a way to walk chained method handles in the JVM to call the right methods and to generate required bytecode adapters for the compilers.

Reviewed-by: kvn

hotspot/src/share/vm/classfile/javaClasses.cpp

@@ -2403,6 +2403,10 @@ oop java_dyn_MethodType::ptype(oop mt, int idx) {
   return ptypes(mt)->obj_at(idx);
 }
 
+int java_dyn_MethodType::ptype_count(oop mt) {
+  return ptypes(mt)->length();
+}
+
 
 
 // Support for java_dyn_MethodTypeForm