8173393: Module system implementation refresh (2/2017)

[Alan Bateman]

We've been accumulating changes in the jake forest for the last few 
weeks and it's time to bring the changes to jdk9/dev, to make jdk-9+157 
if possible. JDK 9 is the first phase of rampdown and so this update 
will need to get approval via the FC-extension process.

The changes this time are significantly smaller than previous updates. 
Much of this update is API and javadoc cleanup. There are a few new 
methods, and a few methods have been renamed/changed, but it's otherwise 
small potatoes.

The webrevs with the changes are here:
    http://cr.openjdk.java.net/~alanb/8173393/1/

Note that the webrevs are against jdk-9+155 because that is what jake is 
currently at. I will re-generate the webrevs later in the week once 
jdk-9+156 is promoted before eventually merging with jdk9/dev in advance 
of the eventual push.

One other thing to note is that the hotspot+jdk repos have the changes 
for JDK-8171855, this is only because that change was backed up in 
jdk9/hs for several weeks and only got to jdk9/dev for jdk-9+156. This 
means that the only non-test change in the hotspot repo is to 
methodHandles.cpp.

In the langtools repo then most of the changes are mechanical, with the 
only real update being cleanup to jdeps and the change to javac + javap 
to use the right values for the requires flags (the issue that Rémi 
brought up on jigsaw-dev last week when sync'ing up ASM).

In the jdk repo then ignore the DEBUG_ADD_OPENS changes in 
ModuleBootstrap, that is not intended for JDK 9.

There are a few small bug fixes, and a few more startup improvements 
from Claes. There are a small number of tests that aren't in jake yet 
for this update but they should be before I refresh the webrev later in 
the week.

-Alan