VM compilation with gcc 4.2.1

[Gregory Shimansky]

Hello

I am back after vacations and didn't catch up with all emails so far, so 
forgive me if this issue was reported already.

I tried to build harmony on my gentoo box which has gcc 4.1.2 and 
compilation failed because of inconsistent declarations of 
p_the_safepoint_control_thread and global_safepoint_status variables. In 
the file vm_threads.h these variables are declared without extern "C", 
so it is considered in C++ mode, and in file thread_manager.cpp they are 
declared in extern "C" clause, so it is plain C style.

Compilation fails because of this inconsistency and so I want to fix it. 
Since this is some code (it comes from rev 556704 by Weldon) that is new 
to me, I have a question which way it is correct to declare 
p_the_safepoint_control_thread and global_safepoint_status variables. 
Should they be C or C++ style variables?

BTW looking at their usage it seems like they are almost deprecated and 
could be removed in the future.

--
Gregory