Auto merge of #45655 - alexcrichton:mips-less-cgus, r=michaelwoerister
Auto merge of #45655 - alexcrichton:mips-less-cgus, r=michaelwoerister

rustbuild: Don't build with ThinLTO on MIPS

Discovered in #45529 it looks like cross-module TLS imports aren't quite working
today, especially with `hidden` visibility which mostly comes up with multiple
codegen units. As a result this completely disables compiling with ThinLTO and
multiple codegen units on MIPS when bootstrapping.

cc #45654, the tracking issue for this

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