Do not suggest operation references in postfix templates

#KT-14087 Fixed

idea/src/org/jetbrains/kotlin/idea/codeInsight/postfix/KtPostfixTemplateProvider.kt

@@ -24,6 +24,7 @@ import com.intellij.openapi.util.Condition
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
 import org.jetbrains.annotations.TestOnly
+import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.intentions.negate
 import org.jetbrains.kotlin.idea.refactoring.introduce.introduceVariable.KotlinIntroduceVariableHandler
@@ -139,10 +140,13 @@ private class KtExpressionPostfixTemplateSelector(
                 it !is KtBlockExpression &&
                 it !is KtDeclarationWithBody &&
                 !it.isEffectivelyDeclaration()
-            }.filter { !it.isSelector && it.parent !is KtUserType }
+            }.filter { !it.isSelector && it.parent !is KtUserType && !it.isOperationReference }
             .toList()
 }
 
+private val KtExpression.isOperationReference: Boolean
+    get() = this.node.elementType == KtNodeTypes.OPERATION_REFERENCE
+
 private fun KtElement.isEffectivelyDeclaration() =
         this is KtNamedDeclaration &&
         // function literal is an expression while it's also a subtype of KtNamedDeclaration