URGENT: Request for review: 7122222: GC log is limited to 2G for 32-bit

[Tao Mao]

7ux bug

webrev:
http://cr.openjdk.java.net/~tamao/7122222/webrev.00/

changeset:
(1) make -D_FILE_OFFSET_BITS=64 only available to generating ostream.o

Why conservative rather than making -D_FILE_OFFSET_BITS=64 globally 
applicable?

Global setting of -D_FILE_OFFSET_BITS=64 on linux works fine; however, 
there are at least five code conflicts if introducing the flag globally 
to Solaris.

One was resolved as in os_solaris.inline.hpp, but the rest four files 
had conflicts deep in c library. Even if they are excluded from setting 
-D_FILE_OFFSET_BITS=64, the compiled VM is corrupted.

(2) For now, no Windows solution.
I haven't found any clean solution for solving this problem on Windows.

test:
(1) Ability to write over 2g file for 32-bit builds were verified on the 
following configurations.

Linux * i586
Solaris * i586
Solaris * sparc

(2) Need a JPRT test for sanity check.