Remove additional function template definitions from the dylib

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285537 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/string b/include/string
index 95fbce0..ee827f6 100644
--- a/include/string
+++ b/include/string
@@ -927,7 +927,7 @@
     basic_string& append(const value_type* __s);
     basic_string& append(size_type __n, value_type __c);
     template <class _ForwardIterator>
-    basic_string& __append_forward_unsafe(_ForwardIterator, _ForwardIterator);
+    inline basic_string& __append_forward_unsafe(_ForwardIterator, _ForwardIterator);
     template<class _InputIterator>
         typename enable_if
         <