cryptography.io wants RSA_R_BLOCK_TYPE_IS_NOT_02, only used by the
ancient RSA_padding_check_SSLv23 function. Define it but never emit it.

Additionally, it's rather finicky about RSA_R_TOO_LARGE* errors. We
merged them in BoringSSL because having RSA_R_TOO_LARGE,
RSA_R_TOO_LARGE_FOR_MODULUS, and RSA_R_TOO_LARGE_FOR_KEY_SIZE is a
little silly. But since we don't expect well-behaved code to condition
on error codes anyway, perhaps that wasn't worth it.  Split them back
up.

Looking through OpenSSL, there is a vague semantic difference:

RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY - Specifically emitted if a digest is
too big for PKCS#1 signing with this key.

RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE - You asked me to sign or encrypt a
digest/plaintext, but it's too big for this key.

RSA_R_DATA_TOO_LARGE_FOR_MODULUS - You gave me an RSA ciphertext or
signature and it is not fully reduced modulo N.
-OR-
The padding functions produced something that isn't reduced, but I
believe this is unreachable outside of RSA_NO_PADDING.

RSA_R_DATA_TOO_LARGE - Some low-level padding function was told to copy
a digest/plaintext into some buffer, but the buffer was too small. I
think this is basically unreachable.
-OR-
You asked me to verify a PSS signature, but I didn't need to bother
because the digest/salt parameters you picked were too big.

Update-Note: This depends on cl/196566462.
Change-Id: I2e539e075eff8bfcd52ccde365e975ebcee72567
Reviewed-on: https://boringssl-review.googlesource.com/28547
Reviewed-by: Adam Langley <agl@google.com>