std: fix compile errors in `std.crypto.ecc` (#23797)
Implemented `neg()` method for `AffineCoordinates` struct of p256,
p384 and secp256k1 curves.
Resolves: #20505 (partially)
b21fa8e2cdHydroH committed on 5/6/2025, 4:03:03 PM· committed by Alex Rønne Petersenparent5cfd476