bpo-45196: prevent unittest crash on address sanitizer builds (GH-28331)

(cherry picked from commit b668cdfa09e9bdfcfddaadd23dbd455d5f667383)

Co-authored-by: junyixie <xiejunyi.arch@bytedance.com>
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 28d5690..99263bb 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -43,6 +43,17 @@
 import random
 import inspect
 import threading
+import sysconfig
+_cflags = sysconfig.get_config_var('CFLAGS') or ''
+_config_args = sysconfig.get_config_var('CONFIG_ARGS') or ''
+MEMORY_SANITIZER = (
+    '-fsanitize=memory' in _cflags or
+    '--with-memory-sanitizer' in _config_args
+)
+
+ADDRESS_SANITIZER = (
+    '-fsanitize=address' in _cflags
+)
 
 
 if sys.platform == 'darwin':
@@ -5500,6 +5511,8 @@ def __abs__(self):
     # Issue 41540:
     @unittest.skipIf(sys.platform.startswith("aix"),
                      "AIX: default ulimit: test is flaky because of extreme over-allocation")
+    @unittest.skipIf(MEMORY_SANITIZER or ADDRESS_SANITIZER, "sanitizer defaults to crashing "
+                     "instead of returning NULL for malloc failure.")
     def test_maxcontext_exact_arith(self):
 
         # Make sure that exact operations do not raise MemoryError due