8307123: Fix deprecation warnings in DPrinter

Backport-of: b76f320e76f0fb58c598fdd7a5937f1b5bb1de15

Author: Amos Shi

test/langtools/tools/javac/lib/DPrinter.java

@@ -600,6 +600,7 @@ protected void indent(int n) {
     protected Object getField(Object o, Class<?> clazz, String name) {
         try {
             Field f = clazz.getDeclaredField(name);
+            @SuppressWarnings("deprecation")
             boolean prev = f.isAccessible();
             f.setAccessible(true);
             try {
@@ -617,6 +618,7 @@ protected Object getField(Object o, Class<?> clazz, String name) {
     protected Object callMethod(Object o, Class<?> clazz, String name) {
         try {
             Method m = clazz.getDeclaredMethod(name);
+            @SuppressWarnings("deprecation")
             boolean prev = m.isAccessible();
             m.setAccessible(true);
             try {