MFC: r265863

libedit: add H_SAVE_FP which saves history to a file pointer.

H_SAVE_FP is similar to H_SAVE but operates on a FILE* instead of a filename.
This is useful when operating in capability mode.

Reviewed by: christos@NetBSD.org, pfg

MFC: r265863

libedit: add H_SAVE_FP which saves history to a file pointer.

H_SAVE_FP is similar to H_SAVE but operates on a FILE* instead of a filename.
This is useful when operating in capability mode.

Reviewed by: christos@NetBSD.org, pfg