[committed] libstdc++: Disable support by default for avr

[Jonathan Wakely via Gcc-patches]

libstdc++-v3/ChangeLog:

        * acinclude.m4 (GLIBCXX_ENABLE_BACKTRACE): Disable by default
        for avr.
        * configure: Regenerate.
---
 libstdc++-v3/acinclude.m4 | 5 ++++-
 libstdc++-v3/configure    | 5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index b7210e09d89..15b3d74ffb7 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -5481,7 +5481,10 @@ BACKTRACE_CPPFLAGS="$BACKTRACE_CPPFLAGS 
-DBACKTRACE_ELF_SIZE=$elfsize"
 
   AC_MSG_CHECKING([whether to build libbacktrace support])
   if test "$enable_libstdcxx_backtrace" = "auto"; then
-    enable_libstdcxx_backtrace="$is_hosted"
+    case "$host" in
+      avr-*-*) enable_libstdcxx_backtrace=no ;;
+      *) enable_libstdcxx_backtrace="$is_hosted" ;;
+    esac
   fi
   AC_MSG_RESULT($enable_libstdcxx_backtrace)
   if test "$enable_libstdcxx_backtrace" = "yes"; then