Revert "Ninja: job pool support for compiling and linking"

This reverts commit a9bf9065f576e8e07861505a20ef800bc4ff8c81.
Merge topic 'ninja-compile-link-pool' into next

4e52cfc Revert "Ninja: job pool support for compiling and linking"
Ninja: job pool support for compiling and linking

Could be tested by setting the environment
variable NINJA_STATUS=[%r]
Merge topic 'ninja-compile-link-pool' into next

529b58d Ninja: job pool support for compiling and linking