Remove UB statement

[fee1-dead]

No description provided.

[rust-highfive]

r? @Mark-Simulacrum

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[bjorn3]

At MIR level division by zero is UB. Explicit checks for 0 are inserted are inserted to allow it to not be UB for the surface language.

https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=1d680261de85ff6b6e19b15d570d636c

// WARNING: This output format is intended for human consumers only// and is subject to change without notice. Knock yourself out.fnfoo(_1:u8,_2:u8) -> u8{
debug a => _1;// in scope 0 at [src/lib.rs:1:8: 1:9](https://play.rust-lang.org/#)
debug b => _2;// in scope 0 at [src/lib.rs:1:15: 1:16](https://play.rust-lang.org/#)letmut _0:u8;// return place in scope 0 at [src/lib.rs:1:25: 1:27](https://play.rust-lang.org/#)letmut _3:u8;// in scope 0 at [src/lib.rs:2:5: 2:6](https://play.rust-lang.org/#)letmut _4:u8;// in scope 0 at [src/lib.rs:2:9: 2:10](https://play.rust-lang.org/#)letmut _5:bool;// in scope 0 at [src/lib.rs:2:5: 2:10](https://play.rust-lang.org/#)
bb0:{
_3 = _1;// scope 0 at [src/lib.rs:2:5: 2:6](https://play.rust-lang.org/#)
_4 = _2;// scope 0 at [src/lib.rs:2:9: 2:10](https://play.rust-lang.org/#)
_5 = Eq(_4,const0_u8);// scope 0 at [src/lib.rs:2:5: 2:10](https://play.rust-lang.org/#)assert(!move _5,"attempt to divide `{}` by zero", _3) -> bb1;// scope 0 at [src/lib.rs:2:5: 2:10](https://play.rust-lang.org/#)}
bb1:{
_0 = Div(move _3,move _4);// scope 0 at [src/lib.rs:2:5: 2:10](https://play.rust-lang.org/#)return;// scope 0 at [src/lib.rs:3:2: 3:2](https://play.rust-lang.org/#)}}

[fee1-dead]

@bjorn3: Thanks for the explanation! I have #94017 up which clarifies the UB part a bit more so that it is easier to understand.