RFR: JDK-8140484: Vardeps broken when variable value contains '$'

[Tim Bell]

Erik:

> When I optimized the vardeps functionality in JDK-8136385, I caused a 
> regression when the variable contained '$' characters. By reading the 
> old value as a makefile using "include", variable substitution is 
> applied. To work around this, dollar characters need to be escaped 
> (doubled) prior to printing the variable value to the vardeps makefile.
>
> This causes native libraries to be relinked every time they are 
> incrementally built because of the "\$ORIGIN" string.
>
> Also updating tests to cover this.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8140484
> Webrev: http://cr.openjdk.java.net/~erikj/8140484/webrev.01/

Looks good to me.

/Tim