Copy the bionic -fstack-protector hack into libbacktrace.

aarch64 doesn't support -fstack-protector yet.

Change-Id: Id1e589742ba074f59d3390d059248c9b371aff58
diff --git a/libbacktrace/Android.mk b/libbacktrace/Android.mk
index 8995fc1..d2fd79e 100644
--- a/libbacktrace/Android.mk
+++ b/libbacktrace/Android.mk
@@ -148,6 +148,11 @@
 	-DGTEST_OS_LINUX_ANDROID \
 	-DGTEST_HAS_STD_STRING \
 
+ifeq ($(TARGET_ARCH),aarch64)
+  $(info TODO: $(LOCAL_PATH)/Android.mk -fstack-protector not yet available for the AArch64 toolchain)
+  LOCAL_CFLAGS += -fno-stack-protector
+endif # aarch64
+
 LOCAL_CONLYFLAGS += \
 	$(common_conlyflags) \