RFR: JDK-8033236 Update GensrcCharsetMapping.gmk to build-infra standards

[Magnus Ihse Bursie]

On 2014-02-04 00:11, Xueming Shen wrote:
> Changeset looks fine. Thanks for doing this.

Thanks for the review.
>
> Potentially it might worth considering to move two template files
> DoubleByte/SingleByte-X.java.template into the corresponding source
> code directory as well. But they can be dealt with later. 

I actually did consider this, but it's not so easy. These files belong 
to "package $PACKAGE", that is, they are generated into different 
places. In such cases, I think they more properly belong in the 
make/data directory. (Or, in this case, since it's just two different 
places they're going to, we could have two copies.) But putting a 
*.java.template file in the src/share/classes tree but not at the place 
where it ends up will just be even worse, I think.

> We should migrate the StandardCharsets generating code from awk/sed to 
> Java
> someday as well.

It would be nice if all preprocessing tools were written in Java, but as 
long as it's well encapsulated and fits into the build structure, that's 
not the biggest issue right now, I think.

/Magnus