Exes
----
Before: The whole bin/ folder was copied which could contain random old/stale/testsuite executables
After: Be precise

Wrappers
--------
Before: Wrappers were created for everything in the bin folder,
including internal executables such as "unlit"
After: Only create wrappers for the specific things which we want to
include in the user's path.

This makes the hadrian bindists match up more closely with the make
bindists.

(cherry picked from commit 888eadb9)