merging with latest jdk7: langtools

[Jonathan Gibbons]

I have merged (but not yet committed and pushed) the latest 
jdk7/tl/langtools into a copy of jigsaw/jigsaw/langtools.

It builds itself OK.
It runs regression tests against a recent JDK7 build OK
-- we need a one line fix in jigsaw/jigsaw/jdk to be able to run 
langtools regression tests with jigsaw jdk.

I have JPRT jobs to build jigsaw (langtools+jdk) awaiting execution.

Assuming all goes well with testing, how do we want to stage the 
execution here: is there any reason not to commit and push this updated 
copy of langtools?

-- Jon