Build: add useIR/useIRForLibraries to kotlin-build-gradle-plugin

dependencies/kotlin-build-gradle-plugin/src/BuildProperties.kt

@@ -101,6 +101,10 @@ class KotlinBuildProperties(
 
     val localBootstrapPath: String? = getOrNull("bootstrap.local.path") as String?
 
+    val useIR: Boolean = getBoolean("kotlin.build.useIR")
+
+    val useIRForLibraries: Boolean = getBoolean("kotlin.build.useIRForLibraries")
+
     val teamCityBootstrapVersion: String? = getOrNull("bootstrap.teamcity.kotlin.version") as String?
 
     val teamCityBootstrapBuildNumber: String? = getOrNull("bootstrap.teamcity.build.number") as String?
@@ -143,4 +147,4 @@ val Settings.kotlinBuildProperties: KotlinBuildProperties
     get() = extensions.findByName(extensionName) as KotlinBuildProperties?
         ?: KotlinBuildProperties(SettingsProperties(this)).also {
             extensions.add(extensionName, it)
-        }
+        }