Build maven-like stdlib sources artifacts during dist

This is needed to emulate gradle and maven like projects in plugin tests.

libraries/stdlib/common/build.gradle

@@ -120,6 +120,7 @@ artifacts {
 // TODO: call the "dist" task instead, once we need to publish kotlin-stdlib-common.jar with the compiler distribution
 task distCommon(type: Copy) {
     from(jar)
+    from(sourcesJar)
     into "$distDir/common"
     rename "-${java.util.regex.Pattern.quote(version)}", ''
 }

libraries/stdlib/jvm/build.gradle

@@ -116,17 +116,26 @@ task distSourcesJar(type: Jar) {
     }
 }
 
+task distMavenSources(type: Copy) {
+    from(sourcesJar)
+    into "$distDir/maven"
+    rename "-${java.util.regex.Pattern.quote(version)}", ''
+}
+
 artifacts {
     archives sourcesJar
     archives javadocJar
 }
 
 dist {
+    dependsOn distMavenSources
+
     [jar, distSourcesJar].forEach {
         from(it) {
             rename('dist-', '')
         }
     }
+
     from (configurations.compile) {
         include 'annotations*.jar'
     }