These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] dev-lang/luajit-2.1.1787165859:2/2.1.1787165859::gentoo  USE="-lua52compat -static-libs" 1078 KiB
[ebuild  N     ] app-benchmarks/wrk-4.2.0::gentoo  LUA_SINGLE_TARGET="luajit" 10717 KiB

Total: 2 packages (2 new), Size of downloads: 11794 KiB