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

This reverts commit 5561d55355ecb5d62335a632561aeecd7d38b587.
Merge topic 'ninja-compile-link-pool' into next

c447ad8 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

2d25655 Ninja: job pool support for compiling and linking