patch 9.0.1075: build fails if compiler doesn't allow declaration after case

Problem:    build fails if the compiler doesn't allow for a declaration right
            after "case".
Solution:   Add a block.
diff --git a/src/vim9instr.c b/src/vim9instr.c
index 8bd2485..4a22d18 100644
--- a/src/vim9instr.c
+++ b/src/vim9instr.c
@@ -2188,29 +2188,32 @@
 	case dest_vimvar:
 	    return generate_STORE(cctx, ISN_STOREV, vimvaridx, NULL);
 	case dest_script:
-	    int	    scriptvar_idx = lhs->lhs_scriptvar_idx;
-	    int	    scriptvar_sid = lhs->lhs_scriptvar_sid;
-	    if (scriptvar_idx < 0)
 	    {
-		isntype_T   isn_type = ISN_STORES;
-
-		if (SCRIPT_ID_VALID(scriptvar_sid)
-			 && SCRIPT_ITEM(scriptvar_sid)->sn_import_autoload
-			 && SCRIPT_ITEM(scriptvar_sid)->sn_autoload_prefix
-								       == NULL)
+		int	    scriptvar_idx = lhs->lhs_scriptvar_idx;
+		int	    scriptvar_sid = lhs->lhs_scriptvar_sid;
+		if (scriptvar_idx < 0)
 		{
-		    // "import autoload './dir/script.vim'" - load script first
-		    if (generate_SOURCE(cctx, scriptvar_sid) == FAIL)
-			return FAIL;
-		    isn_type = ISN_STOREEXPORT;
-		}
+		    isntype_T   isn_type = ISN_STORES;
 
-		// "s:" may be included in the name.
-		return generate_OLDSCRIPT(cctx, isn_type, name,
-						      scriptvar_sid, type);
-	    }
-	    return generate_VIM9SCRIPT(cctx, ISN_STORESCRIPT,
+		    if (SCRIPT_ID_VALID(scriptvar_sid)
+			     && SCRIPT_ITEM(scriptvar_sid)->sn_import_autoload
+			     && SCRIPT_ITEM(scriptvar_sid)->sn_autoload_prefix
+								       == NULL)
+		    {
+			// "import autoload './dir/script.vim'" - load script
+			// first
+			if (generate_SOURCE(cctx, scriptvar_sid) == FAIL)
+			    return FAIL;
+			isn_type = ISN_STOREEXPORT;
+		    }
+
+		    // "s:" may be included in the name.
+		    return generate_OLDSCRIPT(cctx, isn_type, name,
+							  scriptvar_sid, type);
+		}
+		return generate_VIM9SCRIPT(cctx, ISN_STORESCRIPT,
 					   scriptvar_sid, scriptvar_idx, type);
+	    }
 	case dest_class_member:
 	    return generate_CLASSMEMBER(cctx, FALSE,
 				     lhs->lhs_class, lhs->lhs_classmember_idx);