Add missing include statement for compatibility with libstdc++ 11.

Taken from upstream:

  https://github.com/llvm/llvm-project/commit/b498303066a63a203d24f739b2d2e0e56dca70d1

diff --git a/utils/benchmark/src/benchmark_register.h b/utils/benchmark/src/benchmark_register.h
--- a/utils/benchmark/src/benchmark_register.h
+++ b/utils/benchmark/src/benchmark_register.h
@@ -1,6 +1,7 @@
 #ifndef BENCHMARK_REGISTER_H
 #define BENCHMARK_REGISTER_H
 
+#include <limits>
 #include <vector>
 
 #include "check.h"
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<tr><td><span title='2022-07-12 01:17:45 +0200'>2022-07-12</span></td><td><a href='/guix/commit/guix.scm?id=4574ef267e543bcac97d9c400f30cb731df29181'>guix: Really export 'define-public'.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a followup to 3858275962f1ac567b5dce2355035f9eddea0a05, which
didn't have any effect.

* guix.scm: Explicitly use (guix packages) so #:re-export-and-replace
is effective.
</span></span></td><td>Ludovic Courtès</td></tr>