RFR: More cleanup patches

[mandy chung]

On 3/30/18 6:53 PM, Alan Bateman wrote:
>
>>
>> 8200134: Improve ModuleHashesBuilder
>> http://cr.openjdk.java.net/~martin/webrevs/jdk/ModuleHashesBuilder/
>> https://bugs.openjdk.java.net/browse/JDK-8200134
> I suspect Mandy will want to look at this one. We also need to decide 
> if there is a better place for it as it is only used by tools (`jar`, 
> `jmod`, ...), it is not part of the runtime support.

It's in java.base to avoid duplicating this class in both jdk.jar and 
jdk.jlink module.  It's not a small method.  It's not part of the 
runtime support.  I can't think of any better place.

For this change, I am okay with most of the changes except I prefer the 
while loop to the for-loop with the local variable declaration.

Mandy