unguarded field access: support sync expressions (IDEA-153399)

java/java-tests/testData/inspection/guarded/syncOnFieldQualifier.java

@@ -0,0 +1,21 @@
+import javax.annotation.concurrent.GuardedBy;
+
+class Example
+{
+    private final Distribution distribution = new Distribution();
+
+    public void add(long value)
+    {
+        synchronized (distribution) {
+            distribution.total += value;
+            <error descr="Cannot resolve symbol 'total'">total</error> += value;
+        }
+
+    }
+
+    protected static class Distribution
+    {
+        @GuardedBy("this")
+        private long total = 0;
+    }
+}