Java control flow: Fixed false positive for unreachable code in multi-catch clause (IDEA-138978)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting7/IDEA138978.java

@@ -0,0 +1,22 @@
+class MultiCatch {
+
+  public String get(boolean b) {
+    try {
+      return b ? get1() : get2();
+    } catch (EE1 | EE2 e) {
+      return null; // is reachable
+    } catch (E1 | E2 e) {
+      //
+    }
+    return null;
+  }
+
+  String get1() throws E1 { return "1"; }
+  String get2() throws E2 { return "2"; }
+
+  static class E extends Exception { }
+  static class E1 extends E { }
+  static class E2 extends E { }
+  static class EE1 extends E1 { }
+  static class EE2 extends E2 { }
+}