Auto merge of #28249 - stepancheg:get-num-cpus, r=huonw
Auto merge of #28249 - stepancheg:get-num-cpus, r=huonw

No need to export this symbol. `rust_get_num_cpus` is exported.

graydon/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,graydon/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust