Get rid of magic number 16384 in CryptoKeyRSAMac.cpp.
<rdar://problem/29894561>
We have this FIXME: https://searchfox.org/wubkat/rev/af9971e796398c1d012ef5df9a09ed580d19bd17/Source/WebCore/crypto/mac/CryptoKeyRSAMac.cpp#47 // FIXME: We should get rid of magic number 16384. It assumes that the length of provided key will not exceed 16KB. In function 'getPublicKeyComponents'.