fix "Can be replaced with comparison" false positive if extension method called 'equals' is used

Fixes #KT-13480

idea/testData/intentions/conventionNameCalls/replaceCallWithBinaryOperator/equalsExtensionFunction.kt

@@ -0,0 +1,11 @@
+// IS_APPLICABLE: false
+
+class Foo
+
+fun Foo?.equals(other: Foo?) = true
+
+fun bar(f1: Foo?, f2: Foo?) {
+    if (f1.equals<caret>(f2)) {
+
+    }
+}