Make sure the last modified timestamp is set correctly

Linux stores modification time with nano-seconds precision, but we
currently set the timestamp of the cached file only in milliseconds.
This can lead to the situation that the source is considered a few
nanoseconds older than the cache file and therefore the cache is
regenerated every time.

tycho-core/src/main/java/org/eclipse/m2e/pde/target/shared/MavenBundleWrapper.java

@@ -235,7 +235,7 @@ private static WrappedBundle getWrappedNode(DependencyNode node,
                         messages.add(new ProcessingMessage(artifact, Type.WARN, warn));
                     }
                 }
-                wrapArtifactFile.setLastModified(originalFile.lastModified());
+                Files.setLastModifiedTime(wrapArtifactFile.toPath(), Files.getLastModifiedTime(originalFile.toPath()));
                 visited.put(node, wrappedNode = new WrappedBundle(node, depends, key, wrapArtifactFile.toPath(),
                         new Jar(wrapArtifactFile), messages));
             } else {
@@ -301,7 +301,7 @@ public static boolean isOutdated(Path cacheFile, Path sourceFile) throws IOExcep
         if (Files.exists(cacheFile)) {
             FileTime sourceTimeStamp = Files.getLastModifiedTime(sourceFile);
             FileTime cacheTimeStamp = Files.getLastModifiedTime(cacheFile);
-            return sourceTimeStamp.compareTo(cacheTimeStamp) > 0;
+            return sourceTimeStamp.toMillis() > cacheTimeStamp.toMillis();
         }
         return true;
     }