Warn that numba may not work on non-x86

Currently known issues are crashes, not wrong answers, but because
the test setup doesn't allow ignoring crashes but failing on
wrong answers, it would be easy to not notice if this changed

Author: Rebecca N. Palmer <[email protected]>
Forwarded: no


Gbp-Pq: Name numba_warn_nonx86.patch

Author: Debian Science Team

pandas/compat/_optional.py

@@ -4,6 +4,9 @@
 import sys
 from typing import TYPE_CHECKING
 import warnings
+import platform
+import re
+warn_numba_platform = "Non-x86 system detected, Numba may give wrong results or crash" if not bool(re.match('i.?86|x86',platform.uname()[4])) else False
 
 from pandas.util._exceptions import find_stack_level
 
@@ -123,6 +126,8 @@ def import_optional_dependency(
         is ``'warn'`` or ``'ignore'``.
     """
     assert errors in {"warn", "raise", "ignore"}
+    if name=='numba' and warn_numba_platform:
+        warnings.warn(warn_numba_platform)
 
     package_name = INSTALL_MAPPING.get(name)
     install_name = package_name if package_name is not None else name