Create benchmark for light tree FIR builder (including coroutines test)

compiler/fir/lightTree/build.gradle.kts

@@ -1,10 +1,16 @@
+import org.ajoberstar.grgit.Grgit
+
 plugins {
     kotlin("jvm")
     id("org.jetbrains.intellij") version "0.4.5"
+
+    //git plugin
+    id("org.ajoberstar.grgit") version "3.1.1"
 }
 
 group = "org.jetbrains.kotlin.fir"
 val jmhVersion = "1.21"
+val testDataPath = "$rootDir/compiler/fir/lightTree/testData/coroutines"
 
 repositories {
     mavenCentral()
@@ -92,4 +98,17 @@ val jmhExec by tasks.creating(JavaExec::class) {
     systemProperty("idea.home.path", project.intellij.localPath)
     systemProperty("idea.max.intellisense.filesize", 5000 * 1024)
     configurations.plusAssign(project.configurations["compile"])
-}
+}
+
+val deleteGitFolder by tasks.creating(Delete::class) {
+    delete("$testDataPath/.git")
+}
+
+val cloneCoroutines by tasks.creating {
+    val url = "https://github.com/Kotlin/kotlinx.coroutines.git"
+    if (!File(testDataPath).exists()) {
+        Grgit.clone(mapOf("dir" to testDataPath,
+                      "uri" to url)).close()
+    }
+    finalizedBy(tasks["deleteGitFolder"])
+}