Vendor HarfRust and build HarfRust shaping backend in HarfBuzz

Third-party review approved in:
https://groups.google.com/a/google.com/g/chrome-atls-discuss/c/CWb6UNPdrW0/m/fQHEidz-CQAJ

We add the HarfRust Rust implementation of HarfBuzz to develop
towards pixel-perfect matching of the existing shaping behavior
and to evaluate performance compared to the exist C++ shaper
library, with the aim to eventually migrate over. More details
in the third-party review above.

Bug: 427409139
Binary-Size: Rust version added for performance and compat evaluation.
Fuchsia-Binary-Size: See commit message.
Change-Id: I0e73998d23073d79822ef359837945b7445e2252
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7866312
Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1637948}
NOKEYCHECK=True
GitOrigin-RevId: 853d3b977dc85cab06136cccba08e11180881bce

Author: drott

chromium_crates_io/Cargo.lock

@@ -25,6 +25,7 @@ chrono = "0.4.43"
 cxx = "1"
 fend-core = "1"
 font-types = "0.11.3"
+harfrust = "0.8.0"
 hex = "0.4"
 hmac-sha256 = "1.1.12"
 indexmap = "2.12.1"

chromium_crates_io/Cargo.toml

@@ -381,6 +381,9 @@ multiversion_cleanup_bug = "https://crbug.com/493648964"
 allow_first_party_usage = false
 extra_kv = { allow_unsafe = true }
 
+[crate.harfrust]
+extra_kv = { allow_unsafe = false }
+
 [crate.hashbrown.extra_kv]
 # `hashbrown` crate is implicitly trusted because it comes from
 # https://github.com/rust-lang/ (and we already implicitly trust maintainers of

chromium_crates_io/gnrt_config.toml

@@ -0,0 +1 @@
+{"files":{}}

chromium_crates_io/vendor/harfrust-v0_8/.cargo-checksum.json

@@ -0,0 +1,6 @@
+{
+  "git": {
+    "sha1": "d9ca71377d0ab07e805dcd724412d79575f4269e"
+  },
+  "path_in_vcs": "harfrust"
+}