Auto merge of #85521 - alexcrichton:less-tls-inline, r=Mark-Simulacrum
Auto merge of #85521 - alexcrichton:less-tls-inline, r=Mark-Simulacrum

std: Don't inline TLS accessor on MinGW

This is causing [issues] on Cargo's own CI for MinGW and given the
original investigation there's no reason that MinGW should work when
MSVC doesn't, this this tweaks the MSVC exception to being a Windows exception.

[issues]: https://github.com/rust-lang/cargo/runs/2626676503?check_suite_focus=true#step:9:2453

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