[ruby/yarp] rust: Initial yarp-sys

Still need to add more tests

Update Cargo.toml; add README

Switch yp_string_t_type variants to SNAKE_CASE

Add unescape tests

Add encoding callback tests

Add pack_parse test

Add diagnostic test

Add comment test

Add node tests

Add string_list tests

Add other string tests

Add shared string test

Add list tests

Fixes for updated branch

Run bundle install before running Rust tests

Fix version test

ci: Add proper config for rust-toolchain step for sanitizers

ci: Fix tests, clippy

Remove extra `bundle install`; run `bundle exec rake`

Didn't realize `setup-ruby`'s `bundle-cache: true` runs `bundle install`.

Remove `rake compile` from build.rs

This is complicating CI for me; maybe we add it back later.

Undo README formatting changes

Fix UB in C callbacks

Use slice+str instead of String for raw things

Move bindings to bindings module

Handle non-UTF-8 strings in paths

rust ci: test with sanitizers; add -D warnings

Update rust-bindings.yml

Update Cargo.toml

Don't need to compile extra crate_types

PR changes

Apply patch from @kddnewton

Delete unescape_tests.rs

Fix things after rebasing

ruby/prism@273790e40b

.github/workflows/rust-bindings.yml

@@ -0,0 +1,101 @@
+---
+name: Rust Bindings
+
+on:
+  push:
+    paths:
+      - ".github/workflows/rust-bindings.yml"
+      - "include/"
+      - "src/"
+      - "rust/"
+      - "*akefile*"
+    branches:
+      - main
+  pull_request:
+
+env:
+  RUSTFLAGS: "-D warnings"
+
+jobs:
+  cargo-test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: head
+          bundler-cache: true
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml') }}
+          restore-keys: |
+            ${{ runner.os }}-cargo-${{ hashFiles('Cargo.toml') }}
+            ${{ runner.os }}-cargo
+      - name: rake compile
+        run: bundle exec rake compile
+      - name: cargo test
+        working-directory: rust/yarp-sys
+        run: cargo test
+
+  cargo-clippy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: head
+          bundler-cache: true
+      - uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml') }}
+          restore-keys: |
+            ${{ runner.os }}-cargo-${{ hashFiles('Cargo.toml') }}
+            ${{ runner.os }}-cargo
+      - name: rake compile
+        run: bundle exec rake compile
+      - name: cargo clippy
+        working-directory: rust/yarp-sys
+        run: cargo clippy --tests -- -W "clippy::pedantic"
+
+  sanitizer-test:
+    name: Test with -Zsanitizer=${{ matrix.sanitizer }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        sanitizer: [address, leak]
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: head
+          bundler-cache: true
+      - name: rake compile
+        run: bundle exec rake compile
+      - uses: dtolnay/rust-toolchain@nightly
+        with:
+          target: "x86_64-unknown-linux-gnu"
+          components: "rust-src"
+      - name: Test with sanitizer
+        env:
+          RUSTFLAGS: -Zsanitizer=${{ matrix.sanitizer }}
+          RUSTDOCFLAGS: -Zsanitizer=${{ matrix.sanitizer }}
+          # only needed by asan
+          ASAN_OPTIONS: detect_stack_use_after_return=1
+          # Asan's leak detection occasionally complains
+          # about some small leaks if backtraces are captured,
+          # so ensure they're not
+          RUST_BACKTRACE: 0
+        working-directory: rust/yarp-sys
+        run: cargo test -Zbuild-std --verbose --target=x86_64-unknown-linux-gnu