new inference: propagate current substitutors during additional constrains processing (IDEA-118965)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/AdditionalConstraintSubstitution.java

@@ -0,0 +1,19 @@
+import java.util.Map;
+import java.util.function.BinaryOperator;
+import java.util.function.Function;
+import java.util.stream.Collector;
+import java.util.stream.Stream;
+
+public class Bug
+{
+
+  void foo(Stream<Bug> words){
+    words.collect(toMap(w -> 1, (a, b) -> a + b));
+  }
+
+  public static <T, K, U>
+  Collector<T, ?, Map<K,U>> toMap(Function<Bug,  U> valueMapper,
+                                  BinaryOperator<U> mergeFunction) {
+    return null;
+  }
+}