Merge kt files (#1256)

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/relocation/Relocator.kt

@@ -1,5 +1,7 @@
 package com.github.jengelman.gradle.plugins.shadow.relocation
 
+import com.github.jengelman.gradle.plugins.shadow.transformers.CacheableTransformer
+
 /**
  * Modified from [org.apache.maven.plugins.shade.relocation.Relocator.java](https://github.com/apache/maven-shade-plugin/blob/master/src/main/java/org/apache/maven/plugins/shade/relocation/Relocator.java).
  *
@@ -21,3 +23,14 @@ public interface Relocator {
     public val ROLE: String = Relocator::class.java.name
   }
 }
+
+/**
+ * Marks that a given instance of [Relocator] is compatible with the Gradle build cache.
+ * In other words, it has its appropriate inputs annotated so that Gradle can consider them when
+ * determining the cache key.
+ *
+ * @see CacheableTransformer
+ */
+@Retention(AnnotationRetention.RUNTIME)
+@Target(AnnotationTarget.CLASS)
+public annotation class CacheableRelocator

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/transformers/Transformer.kt

@@ -1,5 +1,6 @@
 package com.github.jengelman.gradle.plugins.shadow.transformers
 
+import com.github.jengelman.gradle.plugins.shadow.relocation.CacheableRelocator
 import java.io.IOException
 import org.apache.tools.zip.ZipOutputStream
 import org.gradle.api.Named
@@ -54,6 +55,17 @@ public interface Transformer : Named {
   }
 }
 
+/**
+ * Marks that a given instance of [Transformer] is compatible with the Gradle build cache.
+ * In other words, it has its appropriate inputs annotated so that Gradle can consider them when
+ * determining the cache key.
+ *
+ * @see CacheableRelocator
+ */
+@Retention(AnnotationRetention.RUNTIME)
+@Target(AnnotationTarget.CLASS)
+public annotation class CacheableTransformer
+
 public object NoOpTransformer : Transformer {
   public override fun canTransformResource(element: FileTreeElement): Boolean = false
   public override fun transform(context: TransformerContext): Unit = Unit