46fcac1e4b9e0b1026bc0b663582148b2fd60390 tests: Add fuzzing harness for ec_seckey_import_der(...) and ec_seckey_export_der(...) (practicalswift)
b667a90389cce7e1bf882f4ac78323c48858efaa tests: Add fuzzing harness for SigHasLowR(...) and ecdsa_signature_parse_der_lax(...) (practicalswift)
Pull request description:
Add fuzzing harness for `SigHasLowR(...)` and `ecdsa_signature_parse_der_lax(...)`.
See [`doc/fuzzing.md`](https://github.com/bitcoin/bitcoin/blob/master/doc/fuzzing.md) for information on how to fuzz Bitcoin Core. Don't forget to contribute any coverage increasing inputs you find to the [Bitcoin Core fuzzing corpus repo](https://github.com/bitcoin-core/qa-assets).
Happy fuzzing :)
---
`static` was added to `bool SigHasLowR` in D4467, fuzzer can't link
without removing it
This is a backport of core#19379