diff.c: make built-in hunk header pattern a separate table
diff.c: make built-in hunk header pattern a separate table

This would hopefully make it easier to maintain.  Initially we
would have "java" and "tex" defined, as they are the only ones
we already have.

Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git