Add Clang 16 to CI

.drone.jsonnet

@@ -334,6 +334,14 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
         ["deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-15 main"],
     ),
 
+    linux_pipeline(
+        "Linux 22.04 Clang 16",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-16', CXXSTD: '03,11,14,17,20,2b' },
+        "clang-16",
+        ["deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-16 main"],
+    ),
+
     macos_pipeline(
         "MacOS 10.15 Xcode 12.2 UBSAN",
         { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '03,11,14,1z' } + ubsan,

.github/workflows/ci.yml

@@ -263,6 +263,20 @@ jobs:
               - "https://apt.llvm.org/llvm-snapshot.gpg.key"
             cxxflags: -stdlib=libc++
             linkflags: -stdlib=libc++
+          - toolset: clang
+            compiler: clang++-16
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-22.04
+            install:
+              - clang-16
+              - libc++-16-dev
+              - libc++abi-16-dev
+            sources:
+              - "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-16 main"
+            source_keys:
+              - "https://apt.llvm.org/llvm-snapshot.gpg.key"
+            cxxflags: -stdlib=libc++
+            linkflags: -stdlib=libc++
           - name: UBSAN
             toolset: clang
             compiler: clang++-14