Request for approval: Bugs 6837665 and 6829575

[Andrew Haley]

This is for the OpenJDK 6 trees.

The patch is very similar to that now committed to OpenJDK 7, but it
touches a few more places that control debuginfo.

http://cr.openjdk.java.net/~aph/6829575-jdk6-webrev/

Andrew.