Annotate APIs throwing PNSE on iOS/tvOS/MacCatalyst

[marek-safar]

Following assemblies/types/methods need to be changed to throw PNSE and annotated with System.Runtime.Versioning.UnsupportedOSPlatformAttribute because they are not supported on iOS/tvOS/MacCatalyst

• System.Diagnostics.Process
  • Process.Start + friends (still supported on macCatalyst)
• System.Security.Cryptography.Algorithms (re-implemented in [macOS] Implement RSA, ECC through new macOS 10.12 APIs #51620 and Make DSA.Create, AesCcm, AesGcm, ChaCha20Poly1305 throw PNSE on iOS #52978)
  • All methods referencing libSystem.Security.Cryptography.Native.OpenSsl.dylib
  • AppleCryptoNative_EccGenerateKey
  • AppleCryptoNative_SecKeychainItemCopyKeychain
  • AppleCryptoNative_SecKeychainCreate
  • AppleCryptoNative_SecKeychainDelete
  • AppleCryptoNative_SetKeychainNeverLock
  • AppleCryptoNative_RsaGenerateKey
  • AppleCryptoNative_RsaEncryptOaep
  • AppleCryptoNative_RsaEncryptPkcs
  • AppleCryptoNative_RsaDecryptOaep
  • AppleCryptoNative_RsaDecryptPkcs
  • AppleCryptoNative_SecKeyImportEphemeral
  • AppleCryptoNative_GenerateSignature
  • AppleCryptoNative_GenerateSignatureWithHashAlgorithm
  • AppleCryptoNative_VerifySignature
  • AppleCryptoNative_VerifySignatureWithHashAlgorithm
  • AppleCryptoNative_SecKeyExport
• System.Security.Cryptography.X509Certificates (iOS PAL implemented in [iOS] Implement iOS PAL for S.S.C.X509Certificates #52191)
  • All AppleCryptoNative_* methods as in SSCA
  • AppleCryptoNative_X509ImportCertificate
  • AppleCryptoNative_X509ImportCollection
  • AppleCryptoNative_X509GetRawData
  • AppleCryptoNative_X509ExportData
  • AppleCryptoNative_X509CopyWithPrivateKey
  • AppleCryptoNative_X509MoveToKeychain
  • AppleCryptoNative_X509StoreAddCertificate
  • AppleCryptoNative_X509StoreRemoveCertificate

The fixes should be made in the way that code that depends on native API is never compiled into managed assembly to resolve issues like #47533

Upd. 05/04/21 The latest list of PNSE-throwing APIs - #47910 (comment)

Upd. 06/15/21 The issue has been addressed by re-implementing/re-enabling some previously unsupported API or annotating ones which are still unsupported.

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.