Upstream comparison: Basic support for ByteBufferAs<X>Buffer.

Unlike most ojluni .java files derived from OpenJDK, the six files
ByteBufferAs{Char,Double,Float,Int,Long,Short}Buffer.java
do not correspond 1:1 to an upstream file; upstream instead has
24 .java files generated from a single .template file.

This CL tweaks the upstream tooling to consider those six
files to be derived from ByteBufferAs<X>BufferB.java
(upstream's file specialized on read-write big-endian).

Because of the nonexact correspondence, this is only of
limited use for verification purposes; further work could
potentially improve this ( http://b/111583940#comment4 ).

The benefit of this CL is the upstream comparison tools
will have at least *some* upstream file to compare against,
rather than not being able to find any corresponding upstream
file at all.

Bug: 111583940
Test: Ran libcore-compare-upstream and libcore-copy-upstream-files
      to update snapshots and the verification tracking spreadsheet:

      make libcore-copy-upstream-files && rm -rf ~/ojluni-upstreams && \
      java -jar out/host/linux-x86/framework/libcore-copy-upstream-files.jar \
      ~/ojluni-upstreams

      make libcore-compare-upstreams && java -jar \
      out/host/linux-x86/framework/libcore-compare-upstreams.jar \
      > ~/upstreams.tsv

Change-Id: Iac1f4f0fc593c2d432a2bf4ab5669eed6587c414
1 file changed