Additional fixes for cascades (issue 5146)

compiler/javatests/com/google/dart/compiler/resolver/ResolverTest.java

Index: compiler/javatests/com/google/dart/compiler/resolver/ResolverTest.java
===================================================================
--- compiler/javatests/com/google/dart/compiler/resolver/ResolverTest.java	(revision 13022)
+++ compiler/javatests/com/google/dart/compiler/resolver/ResolverTest.java	(working copy)
@@ -1130,8 +1130,34 @@
         "  }",
         "}"),
         ResolverErrorCode.TYPE_VARIABLE_NOT_ALLOWED_IN_IDENTIFIER);
-   }
+  }
 
+  public void test_cascade_complex() {
+    resolveAndTest(Joiner.on("\n").join(
+        "class Object {}",
+        "class Spline {",
+        "  Spline a() {",
+        "    return this;",
+        "  }",
+        "  Line b() {",
+        "    return null;",
+        "  }",
+        "  Spline f() {",
+        "    Line x = new Line();",
+        "    x.h()..a()..b().g();",
+        "  }",
+        "}",
+        "class Line {",
+        "  Line g() {",
+        "    return this;",
+        "  }",
+        "  Spline h() {",
+        "    return null;",
+        "  }",
+        "}"
+    ));
+  }
+
   /**
    * When {@link SupertypeResolver} can not find "UnknownA", it uses {@link DynamicType}, which
    * returns {@link DynamicElement}. By itself, this is OK. However when we later try to resolve