[7.0.1] Fix output materialized as symlink when building without the …

…bytes.

This appears to have worked in 6.2.x, got broken in 6.3.x, and is working
again at head. The divergence is too great at this point, so it's not possible
to cherry-pick the necessary changes from head. Instead, I've written a
targeted fix that falls back to downloading every target output if at least
one of the outputs was materialized as a symlink.

Fixes bazelbuild#19143.

src/main/java/com/google/devtools/build/lib/remote/RemoteExecutionService.java

@@ -1291,6 +1291,11 @@ private boolean shouldDownload(RemoteActionResult result, PathFragment execPath)
     if (result.getExitCode() != 0) {
       return true;
     }
+    // An output materialized as a symlink might point to one of the other outputs.
+    if (!result.getOutputSymlinks().isEmpty() || !result.getOutputFileSymlinks().isEmpty()
+        || !result.getOutputDirectorySymlinks().isEmpty()) {
+      return true;
+    }
     return remoteOutputChecker.shouldDownloadOutput(execPath);
   }