What does -no-fast-install libtool option do?

[Basin Ilya]

I seek a mode in which libtool would use no wrapper scripts and do the 
following:

- `make all` would create a binary with the debug rpath, just like the 
`-no-install` option does
- `make install` would install a binary without the debug rpath, just like 
without options at all.

The expected drawback is a slower `make install`, but I'm fine with it.

I thought that '-no-fast-install' did that, but it does the opposite: the 
installed binary has the debug rpath and the local executable is a wrapper 
script. Is this really what the authors wanted to do? To me it looks like a 
bug, because I don't see any use in that.

My libtool version is 2.4.6+40+g6ca5e224