Issue #23970: Fixes bdist_wininst not working on non-Windows platform.

command/bdist_wininst.py

@@ -331,7 +331,12 @@ class bdist_wininst(Command):
                 bv = 14.0
         else:
             # for current version - use authoritative check.
+            try:
                 from msvcrt import CRT_ASSEMBLY_VERSION
+            except ImportError:
+                # cross-building, so assume the latest version
+                bv = 14.0
+            else:
                 bv = float('.'.join(CRT_ASSEMBLY_VERSION.split('.', 2)[:2]))