renumbers error testers basing on 5000.

fixed a compiler bug not checking the lower bound of block depth in find_variable_backward_with_word()

t/feed-5003.err

@@ -0,0 +1,9 @@
+## semicolon inside #{} must raise a syntax error
+
+a := #{
+	"k1":
+	"hello k1\n",
+	"k2":
+	"hello k2\n";   ##ERROR: syntax error - unexpected semicolon
+};
+