[libc++][C++03] Cherry-pick #116449 and #113086 (#163362)

Author: philnik777

libcxx/include/__cxx03/vector

@@ -432,10 +432,12 @@ public:
   template <__enable_if_t<__is_allocator<_Allocator>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI vector(size_type __n, const value_type& __x, const allocator_type& __a)
       : __end_cap_(nullptr, __a) {
+    auto __guard = std::__make_exception_guard(__destroy_vector(*this));
     if (__n > 0) {
       __vallocate(__n);
       __construct_at_end(__n, __x);
     }
+    __guard.__complete();
   }
 
   template <class _InputIterator,
@@ -1054,9 +1056,7 @@ inline _LIBCPP_HIDE_FROM_ABI vector<_Tp, _Allocator>::vector(vector&& __x, const
     __x.__begin_ = __x.__end_ = __x.__end_cap() = nullptr;
   } else {
     typedef move_iterator<iterator> _Ip;
-    auto __guard = std::__make_exception_guard(__destroy_vector(*this));
-    assign(_Ip(__x.begin()), _Ip(__x.end()));
-    __guard.__complete();
+    __init_with_size(_Ip(__x.begin()), _Ip(__x.end()), __x.size());
   }
 }
 

libcxx/test/std/containers/sequences/vector/vector.cons/exceptions.pass.cpp

@@ -11,8 +11,6 @@
 // (bug report: https://llvm.org/PR58392)
 // Check that vector constructors don't leak memory when an operation inside the constructor throws an exception
 
-// XFAIL: FROZEN-CXX03-HEADERS-FIXME
-
 #include <cstddef>
 #include <memory>
 #include <type_traits>