Register the gcov "writeout" at init time. Don't list this as a d'tor. Instead,

Register the gcov "writeout" at init time. Don't list this as a d'tor. Instead,
inject some code in that will run via the "__mod_init_func" method that
registers the gcov "writeout" function to execute at exit time.

The problem is that the "__mod_term_func" method of specifying d'tors is
deprecated on Darwin. And it can lead to some ambiguities when dealing with
multiple libraries.
<rdar://problem/11110106>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157852 91177308-0d34-0410-b5e6-96231b3b80d8