This patch was downloaded from https://sft.its.cern.ch/jira/browse/ROOT-7047.
It fixes the build of clang 3.5 with GCC 5.  File paths have been adjusted.

From 00f3ed6eee41da871799ad0fd19153c7682d61fe Mon Sep 17 00:00:00 2001
From: Alexander Klimov <alserkli@inbox.ru>
Date: Mon, 26 Jan 2015 18:45:23 +0200
Subject: [PATCH] [ADT/IntrusiveRefCntPtr] Give friend access to
 IntrusiveRefCntPtr<X> so the relevant move constructor can
 access 'Obj'.

From LLVM upstream:
Author: Argyrios Kyrtzidis <akyrtzi@gmail.com>
Date:   Tue Sep 23 06:06:43 2014 +0000
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218295 91177308-0d34-0410-b5e6-96231b3b80d8
---
 interpreter/llvm/src/include/llvm/ADT/IntrusiveRefCntPtr.h |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/llvm/ADT/IntrusiveRefCntPtr.h b/include/llvm/ADT/IntrusiveRefCntPtr.h
index f9df378..c859c98 100644
--- a/include/llvm/ADT/IntrusiveRefCntPtr.h
+++ b/include/llvm/ADT/IntrusiveRefCntPtr.h
@@ -197,6 +197,9 @@ public:
   private:
     void retain() { if (Obj) IntrusiveRefCntPtrInfo<T>::retain(Obj); }
     void release() { if (Obj) IntrusiveRefCntPtrInfo<T>::release(Obj); }
+
+    template <typename X>
+    friend class IntrusiveRefCntPtr;
   };
 
   template<class T, class U>
-- 
1.7.10.4

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<div class='path'>path: <a href='/guix/log/?id=5a1ebfa32ff4619d87fb0bf01df12a5558c59e24'>root</a>/<a href='/guix/log/gnu?id=5a1ebfa32ff4619d87fb0bf01df12a5558c59e24'>gnu</a>/<a href='/guix/log/gnu/packages.scm?id=5a1ebfa32ff4619d87fb0bf01df12a5558c59e24'>packages.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages.scm?id=5a1ebfa32ff4619d87fb0bf01df12a5558c59e24&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-01-25 18:14:42 +0100'>2023-01-25</span></td><td><a href='/guix/commit/gnu/packages.scm?id=8b2721de6af76780611fe9f86fa5d4cd062400d1'>packages: Adjust 'generate-package-cache' for Guile 3.0.9.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages.scm (generate-package-cache): Adjust for Guile 3.0.9.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-06-06 22:43:30 +0200'>2022-06-06</span></td><td><a href='/guix/commit/gnu/packages.scm?id=635d49f97ee233bbb2673f97d7556c3c91b55889'>packages: Use SRFI-71 instead of SRFI-11.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages.scm (%package-module-path): Use 'let*' instead of
'let*-values'.
(specification-&gt;package, specification-&gt;location)
(specification-&gt;package+output): Use 'let' instead of 'let-values'.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-06-06 22:43:30 +0200'>2022-06-06</span></td><td><a href='/guix/commit/gnu/packages.scm?id=7041fe0646a9603e7d1d6bde139a284146515917'>packages: Add 'specifications-&gt;packages'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages.scm (specifications-&gt;packages): New procedure.
* guix/scripts/home/import.scm (manifest+configuration-files-&gt;code): Use it.
* tests/home-import.scm (match-home-environment-no-services)
(match-home-environment-no-services-nor-packages)
(match-home-environment-bash-service)
(match-home-environment-bash-service-with-alias): Adjust 'packages'
field accordingly.

Co-authored-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Antero Mejr</td></tr>