tests: split out tests of specific decoders
tests: split out tests of specific decoders

Split TESTS into three groups: tests of specific decoders, libunwind
tests, and all other tests.

* tests/Makefile.am (TESTS): Move attach-f-p.test, attach-p-cmd.test,
bexecve.test, count-f.test, count.test, detach-running.test,
detach-sleeping.test, detach-stopped.test, dumpio.test,
filter-unavailable.test, fork-f.test, ksysent.test, opipe.test,
pc.test, qual_syscall.test, redirect.test, restart_syscall.test,
strace-f.test, and vfork-f.test to MISC_TESTS.
Move remaining tests except $(LIBUNWIND_TESTS) to DECODER_TESTS.
Add $(DECODER_TESTS) and $(MISC_TESTS).

cuviper/strace,Saruta/strace,cuviper/strace,Saruta/strace,Saruta/strace,cuviper/strace,cuviper/strace,cuviper/strace,Saruta/strace,Saruta/strace