$NetBSD: patch-aa,v 1.16 2016/06/18 11:26:56 ryoon Exp $

Exclude -flto for gcc 4.1.3 (used in NetBSD/vax 6)
Exclude -flto for gcc 4.4.7 (Used in DragonFly 2.13 - 3.1)
Make -O2 conditional so can be overridden by environment

--- makefile.orig	2012-04-23 16:28:04.000000000 +0000
+++ makefile
@@ -63,7 +63,7 @@ ifeq ($(WIN32),)  #*nix Environments (&&
     OSNAME = windows-build
   endif
   GCC_VERSION = $(shell $(GCC) -v /dev/null 2>&1 | grep 'gcc version' | awk '{ print $$3 }')
-  LTO_EXCLUDE_VERSIONS = 
+  LTO_EXCLUDE_VERSIONS = 4.1.3 4.4.7 4.8.3 4.8.4 4.8.5 5.3.0 5.4.0
   PCAPLIB = pcap
   ifeq (agcc,$(findstring agcc,$(GCC))) # Android target build?
     OS_CCDEFS = -D_GNU_SOURCE
@@ -300,7 +300,7 @@ ifneq ($(DEBUG),)
   CFLAGS_O = -O0
   BUILD_FEATURES = - debugging support
 else
-  CFLAGS_O = -O2
+  CFLAGS_O ?= -O2
   LDFLAGS_O = 
   GCC_MAJOR_VERSION = $(firstword $(subst  ., ,$(GCC_VERSION)))
   ifneq (3,$(GCC_MAJOR_VERSION))