Fix cross-module errors.

Some files in crypto/x509 were moved from crypto/asn1, so they emit errors from
another module. Fix make_errors.go to account for this: cross module errors
must use the foreign module as the first argument to OPENSSL_PUT_ERROR. Both
the function code and the error code should be declared in the foreign module.

Update make_errors.go to ignore cross-module error lines when deciding which
function tokens to emit.

Change-Id: Ic38377ddd56e22d033ef91318c30510762f6445d
Reviewed-on: https://boringssl-review.googlesource.com/3383
Reviewed-by: Adam Langley <agl@google.com>
7 files changed