Build: Make ProGuard task cacheable

Exclude jdk files form libraries input. Instead add jdk major version
to inputs. JavaCompile task acts same to ignore fluctuations in JDK
implementations since api should remain same

libraries/reflect/build.gradle.kts

@@ -5,7 +5,6 @@ import com.github.jengelman.gradle.plugins.shadow.transformers.TransformerContex
 import kotlinx.metadata.jvm.KmModuleVisitor
 import kotlinx.metadata.jvm.KotlinModuleMetadata
 import org.gradle.api.tasks.PathSensitivity.RELATIVE
-import proguard.gradle.ProGuardTask
 import shadow.org.apache.tools.zip.ZipEntry
 import shadow.org.apache.tools.zip.ZipOutputStream
 
@@ -21,6 +20,8 @@ plugins {
     java
 }
 
+val JDK_16: String by rootProject.extra
+
 callGroovy("configureJavaOnlyJvm6Project", project)
 
 publish()
@@ -43,7 +44,6 @@ dependencies {
 
     proguardDeps(kotlinStdlib())
     proguardAdditionalInJars(project(":kotlin-annotations-jvm"))
-    proguardDeps(files(firstFromJavaHomeThatExists("jre/lib/rt.jar", "../Classes/classes.jar", jdkHome = File(property("JDK_16") as String))))
 
     embedded(project(":core:type-system"))
     embedded(project(":kotlin-reflect-api"))
@@ -56,7 +56,7 @@ dependencies {
     embedded(project(":core:util.runtime"))
     embedded("javax.inject:javax.inject:1")
     embedded(protobufLite())
-    
+
     compileOnly("org.jetbrains:annotations:13.0")
 }
 
@@ -139,16 +139,16 @@ val stripMetadata by tasks.registering {
 
 val proguardOutput = "$libsDir/${property("archivesBaseName")}-proguard.jar"
 
-val proguard by task<ProGuardTask> {
+val proguard by task<CacheableProguardTask> {
     dependsOn(stripMetadata)
-    inputs.files(stripMetadata.get().outputs.files)
-    outputs.file(proguardOutput)
 
     injars(mapOf("filter" to "!META-INF/versions/**"), stripMetadata.get().outputs.files)
     injars(mapOf("filter" to "!META-INF/**,!**/*.kotlin_builtins"), proguardAdditionalInJars)
     outjars(proguardOutput)
 
+    jdkHome = File(JDK_16)
     libraryjars(mapOf("filter" to "!META-INF/versions/**"), proguardDeps)
+    libraryjars(firstFromJavaHomeThatExists("jre/lib/rt.jar", "../Classes/classes.jar", jdkHome = jdkHome!!))
 
     configuration("$core/reflection.jvm/reflection.pro")
 }
@@ -202,7 +202,7 @@ val intermediate = when {
 val result by task<Jar> {
     dependsOn(intermediate)
     from {
-        zipTree(intermediate.get().outputs.files.singleFile)
+        zipTree(intermediate.get().singleOutputFile())
     }
     callGroovy("manifestAttributes", manifest, project, "Main")
 }
@@ -210,8 +210,10 @@ val result by task<Jar> {
 val modularJar by task<Jar> {
     dependsOn(intermediate)
     archiveClassifier.set("modular")
-    from(zipTree(intermediate.get().outputs.files.single()))
-    from(zipTree(reflectShadowJar.get().archivePath)) {
+    from {
+        zipTree(intermediate.get().singleOutputFile())
+    }
+    from(zipTree(provider { reflectShadowJar.get().archiveFile.get().asFile })) {
         include("META-INF/versions/**")
     }
     callGroovy("manifestAttributes", manifest, project, "Main", true)