ci: Use cargo-llvm-cov to generate coverage data (#438)

* ci: Use cargo-llvm-cov to generate coverage data

* ci: Remove usage of lld in coverage.yml

* ci: Move codecov.yml to project root

.github/workflows/coverage.yml

@@ -13,51 +13,36 @@ env:
   RUST_TOOLCHAIN: nightly-2022-07-14
 
 jobs:
-  grcov:
+  coverage:
     if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@v2
-      - name: Cache LLVM and Clang
-        id: cache-llvm
-        uses: actions/cache@v3
-        with:
-          path: ./llvm
-          key: llvm
       - uses: arduino/setup-protoc@v1
-      - uses: KyleMayes/install-llvm-action@v1
-        with:
-          version: "14.0"
-          cached: ${{ steps.cache-llvm.outputs.cache-hit }}
       - name: Install toolchain
         uses: actions-rs/toolchain@v1
         with:
           toolchain: ${{ env.RUST_TOOLCHAIN }}
           override: true
-          profile: minimal
+          components: llvm-tools-preview
       - name: Rust Cache
         uses: Swatinem/rust-cache@v2.0.0
       - name: Cleanup disk
         uses: curoky/cleanup-disk-action@v2.0
         with:
-          retain: 'rust,llvm'
-      - name: Execute tests
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --workspace
+          retain: 'rust'
+      - name: Install cargo-llvm-cov
+        uses: taiki-e/install-action@cargo-llvm-cov
+      - name: Collect coverage data
+        run: cargo llvm-cov --lcov --output-path lcov.info
         env:
           RUST_BACKTRACE: 1
           CARGO_INCREMENTAL: 0
-          RUSTFLAGS: "-Zprofile -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Cpanic=unwind -Zpanic_abort_tests -Clink-arg=-fuse-ld=lld"
           GT_S3_BUCKET: ${{ secrets.S3_BUCKET }}
           GT_S3_ACCESS_KEY_ID: ${{ secrets.S3_ACCESS_KEY_ID }}
           GT_S3_ACCESS_KEY: ${{ secrets.S3_ACCESS_KEY }}
           UNITTEST_LOG_DIR: "__unittest_logs"
-      - name: Gather coverage data
-        id: coverage
-        uses: actions-rs/grcov@v0.1
       - name: Codecov upload
         uses: codecov/codecov-action@v2
         with: