Declare generated SourceSets correctly

Allow Gradle to keep the track of the task generating the sources
KTI-1502 Fixed

libraries/stdlib/jvm-minimal-for-test/build.gradle.kts

@@ -1,5 +1,3 @@
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
-
 description = "Kotlin Mock Runtime for Tests"
 
 plugins {
@@ -22,15 +20,6 @@ dependencies {
     builtins(project(":core:builtins"))
 }
 
-sourceSets {
-    "main" {
-        java.apply {
-            srcDir(layout.buildDirectory.dir("src"))
-        }
-    }
-    "test" {}
-}
-
 val copySources by task<Sync> {
     val stdlibProjectDir = file("$rootDir/libraries/stdlib/jvm")
 
@@ -53,7 +42,12 @@ val copySources by task<Sync> {
     into(layout.buildDirectory.dir("src"))
 }
 
-
+sourceSets {
+    "main" {
+        java.srcDir(copySources)
+    }
+    "test" {}
+}
 
 tasks.compileKotlin {
     dependsOn(copySources)

libraries/tools/kotlin-stdlib-gen/build.gradle.kts

@@ -4,18 +4,17 @@ plugins {
 
 val copyrightDirectory = project.layout.buildDirectory.dir("copyright")
 
-sourceSets {
-    "main" {
-        kotlin.srcDir("src")
-        resources.srcDir(copyrightDirectory)
-    }
-}
-
 dependencies {
     api("org.jetbrains.kotlin:kotlin-stdlib:$bootstrapKotlinVersion")
     api("org.jetbrains.kotlin:kotlin-reflect:$bootstrapKotlinVersion")
 }
 
+val copyCopyrightProfile by tasks.registering(Copy::class) {
+    from("$rootDir/.idea/copyright")
+    into(copyrightDirectory)
+    include("apache.xml")
+}
+
 tasks {
     compileKotlin {
         compilerOptions {
@@ -23,16 +22,6 @@ tasks {
         }
     }
 
-    val copyCopyrightProfile by registering(Copy::class) {
-        from("$rootDir/.idea/copyright")
-        into(copyrightDirectory)
-        include("apache.xml")
-    }
-
-    processResources {
-        dependsOn(copyCopyrightProfile)
-    }
-
     register<JavaExec>("run") {
         group = "application"
         mainClass = "generators.GenerateStandardLibKt"
@@ -55,4 +44,11 @@ tasks {
         classpath = sourceSets.main.get().runtimeClasspath
         args = listOf("$rootDir")
     }
-}
+}
+
+sourceSets {
+    "main" {
+        kotlin.srcDir("src")
+        resources.srcDir(copyCopyrightProfile)
+    }
+}