make fails with newer compiler e.g. from latest Ubuntu distro

[simonhf]

$ make
make -f objs/Makefile
make[1]: Entering directory '/home/simon/20180226-swoole-proxy/nginx-perl'
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/nginx.o \
        src/core/nginx.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_log.o \
        src/core/ngx_log.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_palloc.o \
        src/core/ngx_palloc.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_array.o \
        src/core/ngx_array.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_list.o \
        src/core/ngx_list.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_hash.o \
        src/core/ngx_hash.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_buf.o \
        src/core/ngx_buf.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_queue.o \
        src/core/ngx_queue.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_output_chain.o \
        src/core/ngx_output_chain.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_string.o \
        src/core/ngx_string.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_parse.o \
        src/core/ngx_parse.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_inet.o \
        src/core/ngx_inet.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_file.o \
        src/core/ngx_file.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_crc32.o \
        src/core/ngx_crc32.c
cc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused -Werror -g  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
        -o objs/src/core/ngx_murmurhash.o \
        src/core/ngx_murmurhash.c
src/core/ngx_murmurhash.c: In function ‘ngx_murmur_hash2’:
src/core/ngx_murmurhash.c:37:11: error: this statement may fall through [-Werror=implicit-fallthrough=]
         h ^= data[2] << 16;
         ~~^~~~~~~~~~~~~~~~
src/core/ngx_murmurhash.c:38:5: note: here
     case 2:
     ^~~~
src/core/ngx_murmurhash.c:39:11: error: this statement may fall through [-Werror=implicit-fallthrough=]
         h ^= data[1] << 8;
         ~~^~~~~~~~~~~~~~~
src/core/ngx_murmurhash.c:40:5: note: here
     case 1:
     ^~~~
cc1: all warnings being treated as errors
objs/Makefile:448: recipe for target 'objs/src/core/ngx_murmurhash.o' failed
make[1]: *** [objs/src/core/ngx_murmurhash.o] Error 1
make[1]: Leaving directory '/home/simon/20180226-swoole-proxy/nginx-perl'
Makefile:9: recipe for target 'build' failed
make: *** [build] Error 2