This saves about 6-7k of error data.

Change-Id: Ic28593d4a1f5454f00fb2399d281c351ee57fb14
Reviewed-on: https://boringssl-review.googlesource.com/3385
Reviewed-by: Adam Langley <agl@google.com>

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>

Previously, error strings were kept in arrays for each subdirectory and
err.c would iterate over them all and insert them at init time to a hash
table.

This means that, even if you have a shared library and lots of processes
using that, each process has ~30KB of private memory from building that
hash table.

This this change, all the error strings are built into a sorted list and
are thus static data. This means that processes can share the error
information and it actually saves binary space because of all the
pointer overhead in the old scheme. Also it saves the time taken
building the hash table at startup.

This removes support for externally-supplied error string data.

Change-Id: Ifca04f335c673a048e1a3e76ff2b69c7264635be