Fix unrelated tasks being configured at execution time, KT-31666

Replace iteration over all tasks with `.matching { ... }` with `
.configureEach { if (...) ... }`, so that the check iterates
just over those tasks which are triggered to configure from
somewhere else.

Issue #KT-31666 Fixed

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/ConfigurationAvoidanceIT.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.gradle
+
+import org.junit.Test
+
+class ConfigurationAvoidanceIT : BaseGradleIT() {
+
+    @Test
+    fun testUnrelatedTaskNotConfigured() = with(Project("simpleProject", GradleVersionRequired.AtLeast("4.10.2"))) {
+        setupWorkingDir()
+
+        val expensivelyConfiguredTaskName = "expensivelyConfiguredTask"
+        val triggeredExpensiveConfigurationText = "Triggered expensive configuration!"
+
+        gradleBuildScript().appendText("\n" + """
+            tasks.register("$expensivelyConfiguredTaskName") {
+                println("$triggeredExpensiveConfigurationText")
+            }
+        """.trimIndent())
+
+        build("compileKotlin") {
+            assertSuccessful()
+            assertNotContains(triggeredExpensiveConfigurationText)
+        }
+    }
+
+}