Merge bitcoin/bitcoin#28814: test: symbolizer improvements

49d953281d fuzz: explicitly specify llvm-symbolizer path in runner (fanquake)

Pull request description:

  It's not completely clear to me why this needs to be explicitly specified in some environments, and not in others, while at the same time that `llvm-symbolizer` is already in PATH, but this has fixed the 2 issues outlined in https://github.com/bitcoin/bitcoin/pull/28147.

  Use `LLVM_SYMBOLIZER_PATH` as the env var, as that is somewhat also used inside LLVM, but not consistently, i.e it's checked for in the asan_symbolize script, but not in in the ubsan_symbolize script, or from in compiler-rt.

  Alternative to #28804.

ACKs for top commit:
  maflcko:
    lgtm ACK 49d953281d

Tree-SHA512: c3d5bf1c3629793b342c70754a419b3c7a3cd39f800b9aa69ce3395cc2bf83b4d46f2b329974337b94b99573cd0b8600d3f147ed5c21387bf3812316570d1ee3

test/fuzz/test_runner.py

@@ -16,11 +16,14 @@ import sys
 
 
 def get_fuzz_env(*, target, source_dir):
+    symbolizer = os.environ.get('LLVM_SYMBOLIZER_PATH', "/usr/bin/llvm-symbolizer")
     return {
         'FUZZ': target,
         'UBSAN_OPTIONS':
         f'suppressions={source_dir}/test/sanitizer_suppressions/ubsan:print_stacktrace=1:halt_on_error=1:report_error_type=1',
+        'UBSAN_SYMBOLIZER_PATH':symbolizer,
         "ASAN_OPTIONS": "detect_stack_use_after_return=1:check_initialization_order=1:strict_init_order=1",
+        'ASAN_SYMBOLIZER_PATH':symbolizer,
     }