Remove the use of import within when

core/runtime/default_allocators_general.odin

@@ -4,13 +4,16 @@
 //+build !js
 package runtime
 
+// TODO(bill): reimplement these procedures in the os_specific stuff
+import "core:os"
+
 when ODIN_DEFAULT_TO_NIL_ALLOCATOR {
+	_ :: os
+
 	// mem.nil_allocator reimplementation
 	default_allocator_proc :: nil_allocator_proc
 	default_allocator :: nil_allocator
 } else {
-	// TODO(bill): reimplement these procedures in the os_specific stuff
-	import "core:os"
 
 	default_allocator_proc :: os.heap_allocator_proc