Add third party plexi crate

Summary: See title

Reviewed By: cryo28

Differential Revision: D63777232

fbshipit-source-id: 89af639af4a9ac0a8814a491e91966a155ff5511

Cargo.toml

@@ -9,6 +9,7 @@ graphql-parser = { git = "https://github.com/graphql-rust//graphql-parser", rev
 lru-disk-cache = { git = "https://github.com/mozilla/sccache", rev = "fdbf843d174c6796d736b2b61dab0297670390f8" }
 perf-event = { version = "0.4", git = "https://github.com/krallin/perf-event.git", rev = "86224a9bc025d5d19f719542f27c8c629a08b167" }
 perf-event-open-sys = { version = "4.0", git = "https://github.com/krallin/perf-event.git", rev = "86224a9bc025d5d19f719542f27c8c629a08b167" }
+plexi-core = { git = "https://github.com/haochenuw/plexi", rev = "a0326d9802a594ca5382b075620135607e1cdb23" }
 pyo3-build-config = { package = "pyo3-build-config", version = "0.21.2", git = "https://github.com/fbsource/pyo3", rev = "ff94a09031cc29d88d57ae3c846e5b871497aeb9" }
 quickcheck = { git = "https://github.com/jakoschiko/quickcheck", rev = "6ecdf5bb4b0132ce66670b4d46453aa022ea892c" }
 riscv = { git = "https://github.com/rust-embedded/riscv.git", rev = "28e9b02d45827055188be0dbd1f800ba64bc75e6" }