fix native_decide

Author: Kha

src/Lean/Elab/Tactic/ElabTerm.lean

@@ -416,7 +416,7 @@ private unsafe def elabNativeDecideCoreUnsafe (tacticName : Name) (expectedType
     -- disable async codegen so we can catch its exceptions; we don't want to report `evalConst`
     -- failures below when the actual reason was a codegen failure
     withOptions (Elab.async.set · false) do
-      addAndCompile decl
+      addAndCompile (mayPostPoneCompile := false) decl
   catch ex =>
     throwError m!"Tactic `{tacticName}` failed. Error: {ex.toMessageData}"