Moves all of the swift test code into tests/swift (#7509)

Fixes failing tests by regenerating test cases

tests/swift/benchmarks/Sources/benchmarks/main.swift

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import Benchmark
+import CoreFoundation
+import FlatBuffers
+
+benchmark("10Strings") {
+  var fb = FlatBufferBuilder(initialSize: 1<<20)
+  for _ in 0..<1_000_000 {
+    _ = fb.create(string: "foobarbaz")
+  }
+}
+
+benchmark("100Strings") {
+  var fb = FlatBufferBuilder(initialSize: 1<<20)
+  for _ in 0..<1_000_000 {
+    _ = fb.create(string: str)
+  }
+}
+
+benchmark("FlatBufferBuilder.add") {
+  var fb = FlatBufferBuilder(initialSize: 1024 * 1024 * 32)
+  for _ in 0..<1_000_000 {
+    let off = fb.create(string: "T")
+    let s = fb.startTable(with: 4)
+    fb.add(element: 3.2, def: 0, at: 2)
+    fb.add(element: 4.2, def: 0, at: 4)
+    fb.add(element: 5.2, def: 0, at: 6)
+    fb.add(offset: off, at: 8)
+    _ = fb.endTable(at: s)
+  }
+}
+
+benchmark("structs") {
+  let structCount = 1_000_000
+
+  let rawSize = ((16 * 5) * structCount) / 1024
+
+  var fb = FlatBufferBuilder(initialSize: Int32(rawSize * 1600))
+
+  var offsets: [Offset] = []
+  for _ in 0..<structCount {
+    fb.startVector(
+      5 * MemoryLayout<AA>.size,
+      elementSize: MemoryLayout<AA>.alignment)
+    for _ in 0..<5 {
+      _ = fb.create(struct: AA(a: 2.4, b: 2.4))
+    }
+    let vector = fb.endVector(len: 5)
+    let start = fb.startTable(with: 1)
+    fb.add(offset: vector, at: 4)
+    offsets.append(Offset(offset: fb.endTable(at: start)))
+  }
+  let vector = fb.createVector(ofOffsets: offsets)
+  let start = fb.startTable(with: 1)
+  fb.add(offset: vector, at: 4)
+  let root = Offset(offset: fb.endTable(at: start))
+  fb.finish(offset: root)
+}
+
+let str = (0...99).map { _ -> String in "x" }.joined()
+
+@usableFromInline
+struct AA: NativeStruct {
+  public init(a: Double, b: Double) {
+    self.a = a
+    self.b = b
+  }
+  var a: Double
+  var b: Double
+}
+
+Benchmark.main()