include expansions

Author: blink1073

.evergreen/generated_configs/variants.yml

@@ -989,6 +989,8 @@ buildvariants:
     display_name: "* Test Win32"
     run_on:
       - windows-64-vsMulti-small
+    expansions:
+      IS_WIN32: "1"
     tags: [standard-non-linux]
 
   # Storage engine tests

.evergreen/scripts/generate_config.py

@@ -95,7 +95,7 @@ def create_standard_nonlinux_variants() -> list[BuildVariant]:
         if host_name == "win32":
             expansions["IS_WIN32"] = "1"
         display_name = get_variant_name(base_display_name, host)
-        variant = create_variant(tasks, display_name, host=host, tags=tags)
+        variant = create_variant(tasks, display_name, host=host, tags=tags, expansions=expansions)
         variants.append(variant)
 
     return variants