逗号后面 to引导的是什么句子成分

Arya climbed up on the window and sat beside him, to a chorus of thudsand grunts from the yard below.

And he was finding that he had a man’s thirst, to the raucous delightof the youths around him, who urged him on every time he drained a glass.

这两个句子里不定式引导的是什么成分，是做状语么，第二个句子里Who引导的又是什么成分呢?

这两个句子的不定式都表示随着状况，who引导定语从句修饰youths。 raucous delight运用了transferred epithet修辞。