ci: add minimal fast-smoke workflow (crate ny-llvmc EXE smokes)

.github/workflows/fast-smoke.yml

@@ -0,0 +1,64 @@
+name: fast-smoke
+
+on:
+  push:
+    branches: [ "**" ]
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  fast:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Rust (stable)
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Cache cargo
+        uses: Swatinem/rust-cache@v2
+
+      - name: Install LLVM 18 and Python deps
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y curl ca-certificates lsb-release wget gnupg python3-pip
+          curl -fsSL https://apt.llvm.org/llvm.sh -o llvm.sh
+          chmod +x llvm.sh
+          sudo ./llvm.sh 18
+          llvm-config-18 --version
+          python3 -m pip install --upgrade pip
+          python3 -m pip install llvmlite jsonschema
+
+      - name: Build (release)
+        run: |
+          cargo build --release -j 2
+          cargo build --release -p nyash-llvm-compiler -j 2
+          cargo build --release -p nyrt -j 2
+
+      - name: EXE smoke (ternary_basic -> 10)
+        run: |
+          mkdir -p tmp
+          ./target/release/nyash --emit-mir-json tmp/tb.json --backend mir apps/tests/ternary_basic.nyash
+          ./target/release/ny-llvmc --in tmp/tb.json --emit exe --nyrt target/release --out tmp/tb
+          set +e; ./tmp/tb >/dev/null 2>&1; CODE=$?; set -e
+          echo "exit=$CODE"; test "$CODE" -eq 10
+
+      - name: EXE smoke (ternary_nested -> 50)
+        run: |
+          ./target/release/nyash --emit-mir-json tmp/tn.json --backend mir apps/tests/ternary_nested.nyash
+          ./target/release/ny-llvmc --in tmp/tn.json --emit exe --nyrt target/release --out tmp/tn
+          set +e; ./tmp/tn >/dev/null 2>&1; CODE=$?; set -e
+          echo "exit=$CODE"; test "$CODE" -eq 50
+
+      - name: EXE smoke (peek_expr_block -> 1)
+        run: |
+          ./target/release/nyash --emit-mir-json tmp/pb.json --backend mir apps/tests/peek_expr_block.nyash
+          ./target/release/ny-llvmc --in tmp/pb.json --emit exe --nyrt target/release --out tmp/pb
+          set +e; ./tmp/pb >/dev/null 2>&1; CODE=$?; set -e
+          echo "exit=$CODE"; test "$CODE" -eq 1
+