RFR: JDK-8006661 Use LC_ALL=C instead of LANG=C in compare.sh

[Tim Bell]

Magnus:

> We need to use LC_ALL=C instead of LANG=C because the latter does not 
> change LC_MESSAGES, which is necessary if we are grepping for english 
> words in the output from diff.
>
> Webrev:
> http://cr.openjdk.java.net/~ihse/JDK-8006661-use-LC_ALL-in-compare.sh/webrev.01 
>
>

Looks good to me.

/Tim