[Buildroot] [git commit branch/2019.02.x] package/libunwind: add cxx exceptions support

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=484b8cb40c789380e0572b601f01246ecec459c8
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2019.02.x

If C++ is enabled, enable cxx exceptions, so libunwind will implement
_Unwind_GetIP which is used by mono (which already depends on C++)

Fixes:
 - http://autobuild.buildroot.net/results/dbd64c89815d393a4e28b312d74fd80ee6de92da

Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
(cherry picked from commit d5bcb30cf910f13f08f4543cfb0d92a5ec103613)
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
 package/libunwind/libunwind.mk | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/package/libunwind/libunwind.mk b/package/libunwind/libunwind.mk
index 7adf318962..7469b789e3 100644
--- a/package/libunwind/libunwind.mk
+++ b/package/libunwind/libunwind.mk
@@ -11,7 +11,9 @@ LIBUNWIND_LICENSE_FILES = COPYING
 LIBUNWIND_LICENSE = MIT
 LIBUNWIND_AUTORECONF = YES
 
-LIBUNWIND_CONF_OPTS = --disable-tests
+LIBUNWIND_CONF_OPTS = \
+	--disable-tests \
+	$(if $(BR2_INSTALL_LIBSTDCPP),--enable-cxx-exceptions,--disable-cxx-exceptions)
 
 ifeq ($(BR2_PACKAGE_LIBATOMIC_OPS),y)
 LIBUNWIND_DEPENDENCIES = libatomic_ops