Merge bitcoin/bitcoin#27056: doc: use arch agnostic clang path in fuzzing doc (macOS)

b49e19c doc: use arch agnostic clang path in fuzzing doc (macOS) (fanquake)

Pull request description:

  The current path will only work for clang installed via brew on x86_64 macOS.

ACKs for top commit:
  hebasto:
    ACK b49e19c, similar to 7028365.

Tree-SHA512: 8ae4845e1953d5a7178f2b422e2241af1057d8cce1ab79da65df0cd068456dbf85da3489355f81fc4ee09ba602a4b53e989e2dc02476b4abf6c5b3bc3e96473b

Author: MarcoFalke

doc/fuzzing.md

@@ -136,10 +136,10 @@ You may also need to take care of giving the correct path for `clang` and
 `clang++`, like `CC=/path/to/clang CXX=/path/to/clang++` if the non-systems
 `clang` does not come first in your path.
 
-Full configure that was tested on macOS Catalina with `brew` installed `llvm`:
+Full configure that was tested on macOS with `brew` installed `llvm`:
 
 ```sh
-./configure --enable-fuzz --with-sanitizers=fuzzer,address,undefined CC=/usr/local/opt/llvm/bin/clang CXX=/usr/local/opt/llvm/bin/clang++ --disable-asm
+./configure --enable-fuzz --with-sanitizers=fuzzer,address,undefined --disable-asm CC=$(brew --prefix llvm)/bin/clang CXX=$(brew --prefix llvm)/bin/clang++
 ```
 
 Read the [libFuzzer documentation](https://llvm.org/docs/LibFuzzer.html) for more information. This [libFuzzer tutorial](https://github.com/google/fuzzing/blob/master/tutorial/libFuzzerTutorial.md) might also be of interest.