Define BCRYPT_SHA256_ALGORITHM correctly

Author: grynspan

Sources/TestingMacros/Support/CRC32.swift

@@ -82,11 +82,14 @@ private func _crc32(_ bytes: some Sequence<UInt8>) -> UInt32 {
 #if os(Windows)
 /// The shared SHA-256 algorithm provider.
 private nonisolated(unsafe) let _sha256Algorithm: BCRYPT_ALG_HANDLE? = {
-  var alg: BCRYPT_ALG_HANDLE?
-  if 0/*STATUS_SUCCESS*/ == BCryptOpenAlgorithmProvider(&alg, "SHA256"/*BCRYPT_SHA256_ALGORITHM*/, nil, 0) {
-    return alg
+  let sha256AlgorithmName = "SHA256"
+  return sha256AlgorithmName.withCString(encodedAs: UTF16.self) { sha256AlgorithmName in
+    var alg: BCRYPT_ALG_HANDLE?
+    if 0/*STATUS_SUCCESS*/ == BCryptOpenAlgorithmProvider(&alg, sha256AlgorithmName, nil, 0) {
+      return alg
+    }
+    return nil
   }
-  return nil
 }()
 #endif