New comment by leahneukirchen on void-packages repository

https://github.com/void-linux/void-packages/pull/14656#issuecomment-534517459

Comment:
afl: clang-9: error: unknown argument: '-fstack-clash-protection'

Patching that out:

```
echo 0 | ../afl-showmap -m none -q -o .test-instr0 ./test-instr
echo 1 | ../afl-showmap -m none -q -o .test-instr1 ./test-instr

Oops, the instrumentation does not seem to be behaving correctly!

Please ping <lcamtuf@google.com> to troubleshoot the issue.
```