Assert that stack_limit is none.

lib/codegen/src/context.rs

@@ -295,6 +295,10 @@ impl Context {
 
     /// Insert prologue and epilogues after computing the stack frame layout.
     pub fn prologue_epilogue(&mut self, isa: &TargetIsa) -> CtonResult {
+        assert!(
+            self.func.stack_limit.is_none(),
+            "stack_limit isn't implemented yet"
+        );
         isa.prologue_epilogue(&mut self.func)?;
         self.verify_if(isa)?;
         self.verify_locations_if(isa)?;