Add tests for persisting on strace and exiting on sigint

Author: jgkamat

tests/runtime/sigint

@@ -0,0 +1,9 @@
+NAME strace no quit
+RUN bpftrace -v -e 'i:s:1 { printf("%s %d\n", "SUCCESS", 1); exit() }' & (sleep 0.5 && strace -p $! -o /dev/null)
+EXPECT SUCCESS 1
+TIMEOUT 3
+
+NAME sigint quit
+RUN bpftrace -v -e 'END { printf("%s %d", "SUCCESS", 1) }' & (sleep 1 && /usr/bin/env kill -s SIGINT $!)
+EXPECT ^SUCCESS 1$
+TIMEOUT 2