[libc++] Remove vector base class

Remove the vector base class as suggested by @ldionne

Reviewed By: ldionne, Quuxplusone, #libc

Spies: libcxx-commits, ldionne

Differential Revision: https://reviews.llvm.org/D117108
diff --git a/libcxx/src/vector.cpp b/libcxx/src/vector.cpp
index cc3d291..201d4e3 100644
--- a/libcxx/src/vector.cpp
+++ b/libcxx/src/vector.cpp
@@ -10,12 +10,25 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+#ifndef _LIBCPP_ABI_DO_NOT_EXPORT_VECTOR_BASE_COMMON
+
+template <bool>
+struct __vector_base_common;
+
+template <>
+struct __vector_base_common<true> {
+  _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void __throw_length_error() const;
+  _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void __throw_out_of_range() const;
+};
+
 void __vector_base_common<true>::__throw_length_error() const {
-    _VSTD::__throw_length_error("vector");
+  _VSTD::__throw_length_error("vector");
 }
 
 void __vector_base_common<true>::__throw_out_of_range() const {
-    _VSTD::__throw_out_of_range("vector");
+  _VSTD::__throw_out_of_range("vector");
 }
 
+#endif // _LIBCPP_ABI_DO_NOT_EXPORT_VECTOR_BASE_COMMON
+
 _LIBCPP_END_NAMESPACE_STD