[8u20] RFR (L) 8037816+8043029+8043164

[David Chase]

Summary: this is the hotspot side of port to Mavericks + clang, including
turning on all the format annotations (so it won't go stale again)
fixing all the scary bugs flagged by format warnings
fixing quite a few of the harmless warnings flagged by format annotations
disabling gcc's warnings for some files filled with harmless warnings
(but with an ugly flag macro so people can clean it up incrementally)

The intent of the backport is to reduce conflicts for other future backports,
and to wipe clean all the this-can't-be-right mistakes identified by format
warnings (mismatched number of args, that sort of thing).

This webrev includes the original large patch, plus two follow-on patches
for mistakes that were made.  It's been tested as an 8u patch on Mountain Lion,
32- and 64-bit Linux.  It has not been tested on Mavericks with clang 5.1
because whatever attempts have been made to port the build for 8 to Mavericks 
are not there yet (but this should make remove one obstacle, and the warnings
enabled should help keep it from backsliding).

This backport has tracked the 9 patch for most of its existence, and was diff'd
and desk-checked to see that it matches as much as possible.

Bugs:
https://bugs.openjdk.java.net/browse/JDK-8037816 Fix for 8036122 breaks build with Xcode5/clang
https://bugs.openjdk.java.net/browse/JDK-8043029 Change 8037816 breaks HS build with older GCC versions which don't support diagnostic pragmas
https://bugs.openjdk.java.net/browse/JDK-8043164 Format warning in traceStream.hpp

Webrev:
http://cr.openjdk.java.net/~drchase/8037816/webrev-8u.05-21a/