Address review: warning on insertion

Author: liufengyun

tests/neg-custom-args/fatal-warnings/i6190a.check

@@ -0,0 +1,4 @@
+-- Error: tests/neg-custom-args/fatal-warnings/i6190b.scala:3:29 -------------------------------------------------------
+3 |def foo = List("1", "2").map(Rule)  // error
+  |                             ^^^^
+  |      The method `apply` is inserted. The auto insertion will be deprecated, please write `Rule.apply` explicitly.

tests/neg-custom-args/fatal-warnings/i6190b.check

@@ -0,0 +1,3 @@
+case class Rule(name: String)
+
+def foo = List("1", "2").map(Rule)  // error

tests/neg-custom-args/fatal-warnings/i6190b.scala

@@ -0,0 +1,6 @@
+class Rule(name: String)
+object Rule {
+  def apply(name: String): Rule = new Rule(name)
+}
+
+def foo = List("1", "2").map(Rule)  // error

tests/neg/i6190.scala

@@ -0,0 +1,6 @@
+case class Rule(name: String)
+object Rule extends (String => Rule) {
+  def apply(name: String): Rule = new Rule(name)
+}
+
+def foo = List("1", "2").map(Rule)

tests/pos-special/fatal-warnings/i6190a.scala

@@ -0,0 +1,3 @@
+case class Rule(name: String)
+
+def foo = List("1", "2").map(Rule.apply)