6822: Read version of rustc that compiled proc macro r=edwin0cheng a=jsomedon
Signed-off-by: Jay Somedon <jay.somedon@outlook.com>
This PR is to fix#6174.
I basically
* added two methods, `read_version` and `read_section`(used by `read_version`)
* two new crates `snap` and `object` to be used by those two methods
I just noticed that some part of code were auto-reformatted by rust-analyzer on file save. Does it matter?
Co-authored-by: Jay Somedon <jay.somedon@outlook.com>
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>