[clang] [clang][FreeBSD] Enable KASAN and KMSAN for riscv64 (PR #202288)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-aarch64-sve-vls-2stage` running on `arm-bbot-clang-aarch64-sve-vls-2stage` while building `clang` at step 1 "Checkout lnt".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/4/builds/13263

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 1 (Checkout lnt) failure: update (failure) (timed out)
git version 2.43.0
command timed out: 1200 seconds without output running [b'git', b'fetch', b'-f', b'-t', b'https://github.com/llvm/llvm-lnt.git', b'HEAD', b'--progress'], attempting to kill
process killed by signal 15
program finished with exit code -1
elapsedTime=1200.134979
git fetch -f -t https://github.com/llvm/llvm-lnt.git HEAD --progress
 in dir /home/buildbot/workspace/clang-aarch64-sve-vls-2stage/test/lnt (timeout 1200 secs)
 watching logfiles {}
 argv: [b'git', b'fetch', b'-f', b'-t', b'https://github.com/llvm/llvm-lnt.git', b'HEAD', b'--progress']
 environment:
  CC=/usr/local/bin/clang
  CXX=/usr/local/bin/clang++
  HOME=/home/buildbot
  INVOCATION_ID=e8d9f7db32474011ade67eb489fb0812
  JOURNAL_STREAM=10:196664
  LANG=C.UTF-8
  LLVM_ENABLE_PROJECTS=clang
  LOGNAME=buildbot
  MEMORY_PRESSURE_WATCH=/sys/fs/cgroup/system.slice/buildbot-worker.service/memory.pressure
  MEMORY_PRESSURE_WRITE=c29tZSAyMDAwMDAgMjAwMDAwMAA=
  PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/snap/bin
  PWD=/home/buildbot/workspace/clang-aarch64-sve-vls-2stage/test/lnt
  SHELL=/bin/bash
  SYSTEMD_EXEC_PID=46656
  USER=buildbot
 using PTY: False

command timed out: 1200 seconds without output running [b'git', b'fetch', b'-f', b'-t', b'https://github.com/llvm/llvm-lnt.git', b'HEAD', b'--progress'], attempting to kill
process killed by signal 15
program finished with exit code -1
elapsedTime=1200.073566

```

</details>

https://github.com/llvm/llvm-project/pull/202288