Java control flow: Handle the case where the variable from the left part of a compound assignment is modified in the right part of the same assignment (IDEA-23725)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting/LocalVariableInitialization.java

@@ -444,4 +444,12 @@ class AssignInAssert {
     if(<error descr="Variable 'a' might not have been initialized">a</error>)
       System.out.println();
   }
+}
+
+class CompoundAssign {
+  void f() {
+    int i;
+    <error descr="Variable 'i' might not have been initialized">i</error> += i = 2;
+    System.out.println(i);
+  }
 }