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

This reverts commit 2d2565592a8593c4eae5ce15e26621cef2f8c107.
Merge topic 'ninja-compile-link-pool' into next

217e99a 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

2c72c02 Ninja: job pool support for compiling and linking