Some backports of langtools bug fixes likely for b20

[Joseph D. Darcy]

Hello.

FYI, there are a few fixes to langtools that have been made in JDK 7 
there are we are considering backporting the OpenJDK 6 b20:

6548436 java/compiler: Incorrect inconvertible types error
6920317 java/compiler: package-info.java file has to be specified on the 
javac cmdline, else it will not be avail.
6948251: need to quote args in langtools launcher script

-Joe