[3.10] bpo-45355: More use of sizeof(_Py_CODEUNIT) (GH-28720). (GH-28721)

(cherry picked from commit 252b7bcb236dc261f3af1275bc90f9a303d9648f)
diff --git a/Python/compile.c b/Python/compile.c
index b007859..97aa224 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -6619,7 +6619,7 @@ static int
 assemble_line_range(struct assembler *a)
 {
     int ldelta, bdelta;
-    bdelta =  (a->a_offset - a->a_lineno_start) * 2;
+    bdelta =  (a->a_offset - a->a_lineno_start) * sizeof(_Py_CODEUNIT);
     if (bdelta == 0) {
         return 1;
     }