Backported from newer libtool:

From c0c49f289f22ae670066657c60905986da3b555f Mon Sep 17 00:00:00 2001
From: Titus von Boxberg <titus@v9g.de>
Date: Sun, 19 Feb 2012 15:33:48 -0600
Subject: [PATCH] Accept clang's -stdlib linker flag.

--- ltmain.sh.orig	2013-02-15 02:07:57.000000000 -0600
+++ ltmain.sh	2021-06-19 22:25:31.000000000 -0500
@@ -5850,10 +5850,11 @@
       # @file                GCC response files
       # -tp=*                Portland pgcc target processor selection
       # --sysroot=*          for sysroot support
+      # -stdlib=*            select c++ std lib with clang
       # -O*, -flto*, -fwhopr*, -fuse-linker-plugin GCC link-time optimization
       -64|-mips[0-9]|-r[0-9][0-9]*|-xarch=*|-xtarget=*|+DA*|+DD*|-q*|-m*| \
       -t[45]*|-txscale*|-p|-pg|--coverage|-fprofile-*|-F*|@*|-tp=*|--sysroot=*| \
-      -O*|-flto*|-fwhopr*|-fuse-linker-plugin)
+      -O*|-flto*|-fwhopr*|-fuse-linker-plugin|-stdlib=*)
         func_quote_for_eval "$arg"
 	arg="$func_quote_for_eval_result"
         func_append compile_command " $arg"