7122061 review round two: enable -Werror in various jdk build steps

[Stuart Marks]

Hi all, here's any updated webrev for this fix:

     http://cr.openjdk.java.net/~smarks/reviews/7122061/webrev.1/

Changes from the previous webrev:

* I've withdrawn the addition of -Werror from several Makefiles. There are two 
reasons. First, some of these had a single warning, causing javac to emit the 
message "1 warning" that was missed by my analysis script which was looking for 
the string "warnings". Second, some of the steps had zero warnings but the 
addition of closed sources caused warnings to appear. As a result I won't be 
adding -Werror to the following:

     make/com/sun/servicetag/Makefile
     make/java/zip/Makefile
     make/javax/management/Makefile
     make/jpda/bdi/Makefile
     make/sun/pisces/Makefile
     make/sun/tracing/Makefile

* The webrev shows no apparent changes to make/javax/security/Makefile. 
Interesting story here. I saw that this build step had no warnings, so I went 
to add JAVAC_MAX_WARNINGS=true JAVAC_WARNINGS_FATAL=true to the Makefile, and I 
was surprised to discover these declarations already present! Well, they were 
present but with trailing spaces. Turns out that trailing spaces are 
significant in the way that these make variables are used :-( which caused them 
not to be honored. (Make strikes again!) Removing the trailing spaces enables 
the intended behavior.

**

With these changes, 52 out of 93 build steps are warnings-free and have 
-Werror. I do think at some point we should look at having -Werror on by 
default, as David Holmes suggested [1], but some additional cleanup in this 
area is necessary and I want to coordinate with the build infrastructure work 
to see how much effort is appropriate here. Meanwhile I'd prefer to continue in 
a piecemeal approach.

Thanks.

s'marks


[1] http://mail.openjdk.java.net/pipermail/build-dev/2011-December/005301.html