review request (M): 6979327: method handle invocation should use casts instead of type parameters to specify return type

[John Rose]

Javac changes have now propagated for changing this method handle syntax:
  mh.<T>invokeExact()
to be replaced by this:
  (T) mh.invokeExact()

The present reviewe is the "other shoe" dropping for these javac changes, to make the corresponding changes in the JDK code.  All the places which used the old syntax have been replaced by the new.

  http://cr.openjdk.java.net/~jrose/6979327/webrev.jdk.01/

Also in this change set, the class InvokeDynamic has been restored because of linkages to the JVM.  (The previous change, for 6981777, removed it prematurely.)  The restored class is not part of the 292 API, just the implementation.  We'll want to remove the linkages from the JVM.

-- John