RFR (XXS) 8224790: Remove Xusage.txt file

[Alan Bateman]

On 25/05/2019 06:49, David Holmes wrote:
> Bug: https://bugs.openjdk.java.net/browse/JDK-8224790
> webrev: http://cr.openjdk.java.net/~dholmes/8224790/webrev/
>
> Before Java 7 the Xusage.txt file was used to print the "java -X" help 
> information in English. From Java 7 this information was provided in 
> localised format by the launcher. The Xusage.txt file was not removed 
> at the time because it was also used by the gamma launcher. But the 
> gamma launcher was removed in java 8 - JDK-8008772. The information in 
> Xusage.txt has become stale and incomplete (despite several edits post 
> Java 7). It should just be removed.
>
> Also removed the build logic that copied the file into the JDK image.
Looks good to me, I didn't realize Xusage.txt was still in the repo.

-Alan