RFR: JDK-8152959: Build crashes in jdk9-hs-comp on Linux with gnumake 3.81

[Erik Joelsson]

Hello,

The VarHandles change introduced a new gensrc step that crashes when 
using gnumake 3.81. Newer versions of make seem to handle the construct 
in that file. I have found a way to express the makefile, which is a bit 
more correct, and doesn't crash.

The relevant part of the change is the extra dollars inside the eval. An 
eval inside a define that is expected to be called using eval, requires 
double escaping of dollars for correct handling. Most of the time it 
works without though. In this case adding it seems to stop the crashing.

The rest of the change is minor cleanups.

I intend to push this to hs-comp since that's where the varhandles patch 
currently sits.

Bug: https://bugs.openjdk.java.net/browse/JDK-8152959
Webrev: http://cr.openjdk.java.net/~erikj/8152959/webrev.jdk.01/

/Erik