Auto merge of #33526 - steveklabnik:gh21889, r=alexcrichton
Auto merge of #33526 - steveklabnik:gh21889, r=alexcrichton

Add some warnings to std::env::current_exe

/cc #21889 @rust-lang/libs @semarie

I started writing this up. I'm not sure if we want to go into other things and in what depth; we don't currently have a lot of security-specific documentation to model after.

Thoughts?

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