temporarily use cc to link instead of clang to work around issue with -Xarch

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@116435 91177308-0d34-0410-b5e6-96231b3b80d8

lib/buildit

@@ -78,7 +78,7 @@ for FILE in ../src/*.cpp; do
 done
 
 
-$CXX *.o $RC_CFLAGS $LDSHARED_FLAGS 
+cc *.o $RC_CFLAGS $LDSHARED_FLAGS 
 
 #libtool -static -o libc++.a *.o