Log Message:
devel: Add samurai.

samurai is a ninja-compatible build tool written in C99 with a focus on
simplicity, speed, and portability.

samurai implements the ninja build language through version 1.9.0 except
for MSVC dependency handling (`deps = msvc`). It uses the same format
for `.ninja_log` and `.ninja_deps` as ninja, currently version 5 and 4
respectively.

It is feature-complete and supports most of the same options as ninja.

samurai requires various POSIX.1-2008 interfaces.