Filepaths in VM map for tmpfs files

In FreeBSD 9, examining the VM map of a process (with e.g. 'procstat 
-v') with a tmpfs file mapped showed a VNODE type and displayed the file 
path. In 10.0 up to CURRENT (I believe this started at r250030), instead 
SWAP is shown without a filepath.

This has some unfortunate consequences; I discovered this problem when 
trying to use dtrace's pid provider, which fails to find symbols for 
executables running from tmpfs.

I've attached a patch which will repair procstat/dtrace. There are a few 
other places such a patch would be needed. I'm willing to put together 
such a patch, but would like to first hear some feedback that this seems 
like a reasonable approach, or if there's anything I've missed.

Thoughts?

Eric