Ports: Use CMake to build the zstd port

This makes the port install drop the CMake install files into the
sysroot, which is friendlier to macOS users. Homebrew CMake really
likes to pick homebrew zstd, even for cross-builds.

Ports/zstd/package.sh

@@ -3,3 +3,16 @@ port=zstd
 version=1.5.2
 files="https://github.com/facebook/zstd/releases/download/v${version}/zstd-${version}.tar.gz zstd-${version}.tar.gz 7c42d56fac126929a6a85dbc73ff1db2411d04f104fae9bdea51305663a83fd0"
 auth_type=sha256
+useconfigure='true'
+configopts=(
+    "-Sbuild/cmake"
+    "-DCMAKE_TOOLCHAIN_FILE=${SERENITY_BUILD_DIR}/CMakeToolchain.txt"
+)
+
+configure() {
+    run cmake "${configopts[@]}"
+}
+
+install() {
+    run make install
+}