$NetBSD: patch-Makefile,v 1.7 2021/03/05 10:33:14 nia Exp $

Do not mess with the build ENV.

--- Makefile.orig	2021-01-31 11:40:57.000000000 +0000
+++ Makefile
@@ -1,11 +1,9 @@
-CC=gcc
-CFLAGS=-O3 -Wall -Wextra -Wno-unknown-pragmas -Wcast-qual
-LDFLAGS=
+CFLAGS+=-Wall -Wextra -Wno-unknown-pragmas -Wcast-qual
 # CFLAGS=-O3 -Wall -Wextra -Wno-unknown-pragmas -Wcast-qual -g -fsanitize=thread
 # LDFLAGS=-g -fsanitize=thread
 # CFLAGS=-O3 -Wall -Wextra -Wno-unknown-pragmas -Wcast-qual -g -fsanitize=address
 # LDFLAGS=-g -fsanitize=address
-LIBS=-lm -lpthread -lz
+LIBS+=-lm -lpthread -lz
 ZOPFLI=zopfli/src/zopfli/
 ZOP=deflate.o blocksplitter.o tree.o lz77.o cache.o hash.o util.o squeeze.o katajainen.o symbols.o