functional interfaces: allow intersection with 2 independent abstract methods with same signature (IDEA-171622)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/functionalInterface/IntersectionOf2FunctionalTypesWithEqualAfterSubstitutionSignatures.java

@@ -0,0 +1,13 @@
+interface X  {
+  void m(Integer i);
+}
+
+interface Y<T> {
+  void m(T t);
+}
+
+class Test {
+  {
+    ((X & <caret>Y<Integer>) (x) -> {}).m(1);
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/functionalInterface/IntersectionOf2FunctionalTypesWithEqualSignatures.java

@@ -0,0 +1,13 @@
+interface X  {
+  void m();
+}
+
+interface Y {
+  void m();
+}
+
+class Test {
+  {
+    ((X & <caret>Y) () -> {}).m();
+  }
+}