Fail on duplicate file when packing runtime sources for jvm

Fail on duplicate when packing kotlin-jslib.jar and kotlin-jslib-sources.jar
Move files from root of stdlib to avoid existing conflicts
Rename System to SystemJvm to avoid including to js lib

build.xml

@@ -304,7 +304,7 @@
             </externs>
         </closure-compiler>
 
-        <jar jarfile="${kotlin-home}/lib/kotlin-jslib.jar">
+        <jar jarfile="${kotlin-home}/lib/kotlin-jslib.jar" duplicate="fail">
             <resources refid="js.lib.files" />
             <zipfileset file="${kotlin-home}/build.txt" prefix="META-INF"/>
             <zipfileset file="${output}/kotlin.js" prefix=""/>
@@ -322,7 +322,7 @@
     </target>
 
     <target name="pack-js-stdlib-sources">
-        <jar destfile="${kotlin-home}/lib/kotlin-jslib-sources.jar">
+        <jar destfile="${kotlin-home}/lib/kotlin-jslib-sources.jar" duplicate="fail">
             <resources refid="js.lib.files" />
             <fileset refid="kotlin.builtin.files" />
 
@@ -759,7 +759,7 @@
     </target>
 
     <target name="pack-runtime-sources">
-        <jar destfile="${kotlin-home}/lib/kotlin-runtime-sources.jar">
+        <jar destfile="${kotlin-home}/lib/kotlin-runtime-sources.jar" duplicate="fail">
             <fileset dir="${basedir}/core/builtins/native" includes="**/*"/>
             <fileset dir="${basedir}/core/builtins/src" includes="**/*"/>
             <fileset dir="${basedir}/core/runtime.jvm/src" includes="**/*"/>

jslib_files.xml

@@ -29,7 +29,6 @@
             <exclude name="kotlin/io/**" />
             <exclude name="kotlin/math/**" />
             <exclude name="kotlin/template/**" />
-            <exclude name="kotlin/util/**" />
 
             <!-- Temporary disabled -->
             <!--TODO fix: (84, 27) Unresolved reference: copyOf (_SpecialJVM.kt)-->