Change compatibility_version

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@141391 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/buildit b/lib/buildit
index 0b191f3..d6e6afc 100755
--- a/lib/buildit
+++ b/lib/buildit
@@ -35,7 +35,7 @@
   RC_ProjectSourceVersion=1
 fi
 
-EXTRA_FLAGS="-std=c++0x "
+EXTRA_FLAGS="-std=c++0x -Wglobal-constructors"
 
 case $TRIPLE in
   *-apple-*)
@@ -70,7 +70,8 @@
 		fi
 	    LDSHARED_FLAGS="-o libc++.1.dylib \
 			-dynamiclib -nodefaultlibs  \
-			-current_version ${RC_ProjectSourceVersion} -compatibility_version 1 \
+			-current_version ${RC_ProjectSourceVersion} \
+			-compatibility_version ${RC_ProjectSourceVersion} \
 			-install_name /usr/lib/libc++.1.dylib \
 			-lSystem  \
 			-Wl,-unexported_symbols_list,libc++unexp.exp  \