move pffft

Packages/PFFFT/Package.swift

@@ -0,0 +1,35 @@
+// swift-tools-version: 6.0
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "PFFFT",
+    products: [
+        // Products define the executables and libraries a package produces, making them visible to other packages.
+        .library(
+            name: "PFFFT",
+            targets: ["PFFFT", "PFFFTLib"]
+        ),
+    ],
+    targets: [
+        .target(
+            name: "PFFFTLib",
+            publicHeadersPath: "include",
+            cSettings: [
+                .define("PFFFT_SCALVEC_ENABLED", to: "1"),
+                .define("_USE_MATH_DEFINES"),
+                .define("NDEBUG"),
+                .unsafeFlags(["-O3", "-std=c99"]),
+            ]
+        ),
+        .target(
+            name: "PFFFT",
+            dependencies: ["PFFFTLib"]
+        ),
+        .testTarget(
+            name: "PFFFTTests",
+            dependencies: ["PFFFTLib"]
+        ),
+    ]
+)