[NFC][libc++] Update comments to reflect changes in ASan

[AdvenamTacet]

Summary

ASan capabilities were extended, but some comments were not updated and describe old behavior. This commit updates outdated comments, which I found.
Mentioned changes are:

• All allocators in containers (std::vector and std::deque; D146815 D136765) are supported, but it's possible to turn off annotations for a specific allocator (D145628).
• Buffers don't have to be aligned (D132522).

[AdvenamTacet]

Thx for fast review!

libcxx/include/deque

private:
    };
 
    enum __asan_annotation_place {
      __asan_front_moved,
      __asan_back_moved,
    };
 
 // The following functions are no-ops outside of AddressSanitizer mode.
-// We call annotations only for the default Allocator.
+// We call annotations for every allocator, unless explicitly disabled.
+//
+// To disable annotations for a particular allocator, change value of
+// __asan_annotate_container_with_allocator to false.
+// For more details, see the "Using libc++" documentation page or
+// the documentation for __sanitizer_annotate_contiguous_container.
 #if !defined(_LIBCPP_HAS_NO_ASAN) && _LIBCPP_CLANG_VER >= 1600
     // TODO LLVM18: Remove the special-casing
     _LIBCPP_HIDE_FROM_ABI void __annotate_double_ended_contiguous_container(
         const void* __beg,
         const void* __end,
         const void* __old_con_beg,
         const void* __old_con_end,
         const void* __new_con_beg,

libcxx/include/vector

private:
     _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
     inline void __push_back_slow_path(_Up&& __x);
 
     template <class... _Args>
     _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
     inline void __emplace_back_slow_path(_Args&&... __args);
 
     // The following functions are no-ops outside of AddressSanitizer mode.
-    // We call annotatations only for the default Allocator because other allocators
-    // may not meet the AddressSanitizer alignment constraints.
-    // See the documentation for __sanitizer_annotate_contiguous_container for more details.
+    // We call annotations for every allocator, unless explicitly disabled.
+    //
+    // To disable annotations for a particular allocator, change value of
+    // __asan_annotate_container_with_allocator to false.
+    // For more details, see the "Using libc++" documentation page or
+    // the documentation for __sanitizer_annotate_contiguous_container.
 #ifndef _LIBCPP_HAS_NO_ASAN
     _LIBCPP_CONSTEXPR_SINCE_CXX20
     void __annotate_contiguous_container(const void *__beg, const void *__end,
                                          const void *__old_mid,
                                          const void *__new_mid) const
     {
       if (!__libcpp_is_constant_evaluated() && __beg != nullptr && __asan_annotate_container_with_allocator<_Allocator>::value)
         __sanitizer_annotate_contiguous_container(__beg, __end, __old_mid, __new_mid);