functional expressions: allow to delete/change signature of default methods of functional interfaces

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/changeSignature/DefaultMethodTouched.java

@@ -0,0 +1,12 @@
+interface SAM {
+  default void <caret>foo(){}
+  void bar();
+}
+
+class Test {
+  {
+    bar(() -> {});
+  }
+  
+  void bar(SAM sam){}
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/changeSignature/DefaultMethodTouched_after.java

@@ -0,0 +1,12 @@
+interface SAM {
+  default void foo(boolean b){}
+  void bar();
+}
+
+class Test {
+  {
+    bar(() -> {});
+  }
+  
+  void bar(SAM sam){}
+}