ReleaseNotes: update links to use https

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@341789 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index 3b405cd..7e8e307 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -6,13 +6,13 @@
    :local:
    :depth: 2
 
-Written by the `Libc++ Team <http://libcxx.llvm.org>`_
+Written by the `Libc++ Team <https://libcxx.llvm.org>`_
 
 .. warning::
 
    These are in-progress notes for the upcoming libc++ 8 release.
    Release notes for previous releases can be found on
-   `the Download Page <http://releases.llvm.org/download.html>`_.
+   `the Download Page <https://releases.llvm.org/download.html>`_.
 
 Introduction
 ============
@@ -21,16 +21,16 @@
 part of the LLVM Compiler Infrastructure, release 8.0.0. Here we describe the
 status of libc++ in some detail, including major improvements from the previous
 release and new feature work. For the general LLVM release notes, see `the LLVM
-documentation <http://llvm.org/docs/ReleaseNotes.html>`_. All LLVM releases may
-be downloaded from the `LLVM releases web site <http://llvm.org/releases/>`_.
+documentation <https://llvm.org/docs/ReleaseNotes.html>`_. All LLVM releases may
+be downloaded from the `LLVM releases web site <https://llvm.org/releases/>`_.
 
 For more information about libc++, please see the `Libc++ Web Site
-<http://libcxx.llvm.org>`_ or the `LLVM Web Site <http://llvm.org>`_.
+<https://libcxx.llvm.org>`_ or the `LLVM Web Site <https://llvm.org>`_.
 
 Note that if you are reading this file from a Subversion checkout or the
 main Libc++ web page, this document applies to the *next* release, not
 the current one. To see the release notes for a specific release, please
-see the `releases page <http://llvm.org/releases/>`_.
+see the `releases page <https://llvm.org/releases/>`_.
 
 What's New in Libc++ 8.0.0?
 ===========================