[gcc r11-6073] libstdc++: Disabling AC_LIBTOOL_DLOPEN check if building with avr-libc

[Jonathan Wakely]

https://gcc.gnu.org/g:a929b39aa32a6bc65158bd8e32ce96bc1c906065

commit r11-6073-ga929b39aa32a6bc65158bd8e32ce96bc1c906065
Author: Vladimir Vishnevsky <vv.os.swe@gmail.com>
Date:   Tue Dec 15 11:40:07 2020 +0000

    libstdc++: Disabling AC_LIBTOOL_DLOPEN check if building with avr-libc
    
    The AC_LIBTOOL_DLOPEN checks were previously disabled for newlib targets.
    The patch applies similar logic to avr-libc based builds.
    
    libstdc++-v3/ChangeLog:
    
            * configure.ac: Skip AC_LIBTOOL_DLOPEN check if avr-libc is used.
            * configure: Regenerate.

Diff:
---
 libstdc++-v3/configure    | 2 +-
 libstdc++-v3/configure.ac | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index d7a4826b8e2..e6f30a1a706 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -5899,7 +5899,7 @@ $as_echo "$as_me: OS config directory is $os_include_dir" >&6;}
 
 
 # Libtool setup.
-if test "x${with_newlib}" != "xyes"; then
+if test "x${with_newlib}" != "xyes" && test "x${with_avrlibc}" != "xyes"; then
   enable_dlopen=yes
 
 
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index cbfdf4c6bad..771814110a1 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -90,7 +90,7 @@ AC_SYS_LARGEFILE
 GLIBCXX_CONFIGURE
 
 # Libtool setup.
-if test "x${with_newlib}" != "xyes"; then
+if test "x${with_newlib}" != "xyes" && test "x${with_avrlibc}" != "xyes"; then
   AC_LIBTOOL_DLOPEN
 fi
 AM_PROG_LIBTOOL