TCP unit tests broke ia64 build

[Jakub Jermář]

The CI tests ​discovered a breakage of the ia64 build. A closer look reveals that the introduction of the TCP unit tests broke the build on all platforms that don't use --gc-sections during linking. This currently includes only ia64 and abs32le. The build of the tcp service ends with the follow error:

/usr/local/cross/ia64/bin/ia64-pc-linux-gnu-ld -n --fatal-warnings -T ../../../lib/c/arch/ia64/_link.ld -M -Map test-tcp.map -o test-tcp conn.test.o iqueue.test.o ncsim.test.o pdu.test.o rqueue.test.o segment.test.o seq_no.test.o test.test.o tqueue.test.o ucall.test.o test/iqueue.test.o test/main.test.o test/pdu.test.o test/segment.test.o test/seq_no.test.o ../../../lib/pcut/libpcut.a  ../../../lib/nettl/libnettl.a ../../../lib/c/libc.a ../../../lib/softint/libsoftint.a
tqueue.test.o: In function `tcp_transmit_segment':
/home/jermar/software/HelenOS.mainline/uspace/srv/net/tcp/tqueue.c:308: undefined reference to `tcp_transmit_pdu'
/home/jermar/software/HelenOS.mainline/uspace/srv/net/tcp/tqueue.c:308: undefined reference to `tcp_transmit_pdu'
/home/jermar/software/HelenOS.mainline/uspace/srv/net/tcp/tqueue.c:308: undefined reference to `tcp_transmit_pdu'
/home/jermar/software/HelenOS.mainline/uspace/srv/net/tcp/tqueue.c:308: undefined reference to `tcp_transmit_pdu'
make[2]: *** [../../../Makefile.common:367: test-tcp] Error 1
make[2]: Leaving directory '/home/jermar/software/HelenOS.mainline/uspace/srv/net/tcp'
make[1]: *** [Makefile:284: srv/net/tcp.build-test] Error 2
make[1]: Leaving directory '/home/jermar/software/HelenOS.mainline/uspace'
make: *** [Makefile:52: all] Error 2

The missing symbol tcp_transmit_pdu is defined in tcp.c. However, adding this file to the test sources is problematic because it also defines main, which would become duplicit for the test.

[Jiri Svoboda]

Fixed in changeset:mainline,2730