add task to zip stdlib sources, extract&reuse code

backend.native/build.gradle

@@ -156,6 +156,26 @@ task unzipStdlibSources(type: Copy) {
     destinationDir commonSrc
 }
 
+final List<File> stdLibSrc = [
+        project(':Interop:Runtime').file('src/main/kotlin'),
+        project(':Interop:Runtime').file('src/native/kotlin'),
+        project(':Interop:JsRuntime').file('src/main/kotlin'),
+        project(':runtime').file('src/main/kotlin')
+]
+
+task zipStdLibSources(type: Zip, dependsOn: unzipStdlibSources) {
+    from stdLibSrc, {
+        into "native"
+    }
+
+    from commonSrc, { 
+        into "common"
+    }
+
+    archiveName 'kotlin-stdlib-native-sources.zip'
+    destinationDir buildDir
+}
+
 // These files are built before the 'dist' is complete,
 // so we provide custom values for
 // konan.home, --runtime, -Djava.library.path etc
@@ -186,14 +206,8 @@ targetList.each { target ->
                 '-Xallow-result-return-type',
                 commonSrc.absolutePath,
                 "-Xcommon-sources=${commonSrc.absolutePath}",
-                project(':Interop:Runtime').file('src/main/kotlin'),
+                *stdLibSrc]
-                project(':Interop:Runtime').file('src/native/kotlin'),
+        stdLibSrc.forEach { inputs.dir(it) }
-                project(':Interop:JsRuntime').file('src/main/kotlin'),
-                project(':runtime').file('src/main/kotlin')]
-        inputs.dir(project(':runtime').file('src/main/kotlin'))
-        inputs.dir(project(':Interop:Runtime').file('src/main/kotlin'))
-        inputs.dir(project(':Interop:Runtime').file('src/native/kotlin'))
-        inputs.dir(project(':Interop:JsRuntime').file('src/main/kotlin'))
         inputs.dir(commonSrc)
         outputs.dir(project(':runtime').file("build/${target}Stdlib"))