refactor OP_RETURN switch to remove a redundant label and avoid goto

src/vm.c

@@ -1184,8 +1184,19 @@ mrb_run(mrb_state *mrb, struct RProc *proc, mrb_value self)
         mrb_value v = regs[GETARG_A(i)];
 
         switch (GETARG_B(i)) {
+        case OP_R_RETURN:
+          // Fall through to OP_R_NORMAL otherwise
+          if (proc->env && !MRB_PROC_STRICT_P(proc)) {
+            struct REnv *e = top_env(mrb, proc);
+
+            if (e->cioff < 0) {
+              localjump_error(mrb, "return");
+              goto L_RAISE;
+            }
+            ci = mrb->ci = mrb->cibase + e->cioff;
+            break;
+          }
         case OP_R_NORMAL:
-	NORMAL_RETURN:
           if (ci == mrb->cibase) {
             localjump_error(mrb, "return");
             goto L_RAISE;
@@ -1199,19 +1210,6 @@ mrb_run(mrb_state *mrb, struct RProc *proc, mrb_value self)
           }
           ci = mrb->ci = mrb->cibase + proc->env->cioff + 1;
           break;
-        case OP_R_RETURN:
-	  if (!proc->env) goto NORMAL_RETURN;
-	  if (MRB_PROC_STRICT_P(proc)) goto NORMAL_RETURN;
-	  else {
-	    struct REnv *e = top_env(mrb, proc);
-
-	    if (e->cioff < 0) {
-	      localjump_error(mrb, "return");
-	      goto L_RAISE;
-	    }
-	    ci = mrb->ci = mrb->cibase + e->cioff;
-	  }
-          break;
         default:
           /* cannot happen */
           break;