type crypto/internal/nistec/fiat.p384Int1

one use

	crypto/internal/nistec/fiat (current package)
		p384_fiat64.go#L44: type p384Int1 int64   // We use uint64 instead of a more narrow type for performance reasons; see https://github.com/mit-plv/fiat-crypto/pull/1006#issuecomment-892625927