Move File.separatorChar to File.separator to fix GWT issue

Author: lgemeinhardt

src/com/google/javascript/jscomp/SourceFile.java

@@ -359,13 +359,13 @@ public static List<SourceFile> fromZipFile(String zipName, Charset inputCharset)
   private static final String JAR_URL_PREFIX = "jar:file:";
 
   private static boolean isZipEntry(String path) {
-    return path.contains(".zip!" + File.separatorChar) && (path.endsWith(".js") || path.endsWith(".js.map"));
+    return path.contains(".zip!" + File.separator) && (path.endsWith(".js") || path.endsWith(".js.map"));
   }
 
   @GwtIncompatible("java.io.File")
   private static SourceFile fromZipEntry(String zipURL, Charset inputCharset) {
     checkArgument(isZipEntry(zipURL));
-    String[] components = zipURL.split(Pattern.quote(BANG_SLASH.replace('/',  File.separatorChar)));
+    String[] components = zipURL.split(Pattern.quote(BANG_SLASH.replace("/",  File.separator)));
     try {
       String zipPath = components[0];
       String relativePath = components[1];
@@ -379,7 +379,7 @@ private static SourceFile fromZipEntry(String zipURL, Charset inputCharset) {
   public static SourceFile fromZipEntry(
       String originalZipPath, String absoluteZipPath, String entryPath, Charset inputCharset)
       throws MalformedURLException {
-    String zipEntryPath = JAR_URL_PREFIX + absoluteZipPath + BANG_SLASH + entryPath.replace(File.pathSeparatorChar,  '/');
+    String zipEntryPath = JAR_URL_PREFIX + absoluteZipPath + BANG_SLASH + entryPath.replace(File.pathSeparator,  "/");
     URL zipEntryUrl = new URL(zipEntryPath);
 
     return builder()