new inference: cache lambda functional type during expression constraints reduction (IDEA-121315)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/IDEA121315.java

@@ -0,0 +1,22 @@
+import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class IDEA121315 {
+  class Issue {
+    Long getId() {
+      return 1l;
+    }
+  }
+
+  <T> T id(T i) {
+    return i;
+  }
+
+  void foo(Stream<Issue> map){
+    Map<Long, Issue> id2Issue = map.collect(Collectors.toMap(null, p -> id(p)));
+    Map<Long, Issue> id2Issue1 = map.collect(Collectors.toMap(null, p -> p));
+    Map<Long, Issue> id2Issue2 = map.collect(Collectors.toMap(null, this::id));
+
+  }
+}