In some ways, it was just another lunchtime rush at the Bus Stop Pub: Joyce Hynds carried plates of fried clams and Delmonico steak to the regulars seated at the bar and the construction workers in the booths, while Linda Gillis cracked open bottles of Bud Light and Miller. But this was not just another lunchtime: Hynds was crying as she worked, and hugging every customer she served. After 38 years, the Bus Stop will close Saturday, and Friday was a time to mourn the disappearance of a classic Boston institution — the blue-collar neighborhood bar — and the changing makeup of the Allston neighborhood that once sustained it. “Not too many neighborhood bars left,’’ said Gillis, who has tended the Bus Stop bar for 29 years and met her husband, Frank Harrington, when he was the cook, turning out London broil in the little kitchen in back. “It’s terrible. I’m trying not to cry.’’ Close The biggest headlines, delivered to your inbox Get news as it happens. Sign up for Boston.com’s email news alerts. Thanks for signing up!