Remove all the PartialEq<Value> impls for standard library types

[dtolnay]

Currently we have:

• impl PartialEq<Value> for str
• impl PartialEq<Value> for &str
• impl PartialEq<Value> for String
• impl PartialEq<Value> for i8
• impl PartialEq<Value> for i16
• impl PartialEq<Value> for i32
• impl PartialEq<Value> for i64
• impl PartialEq<Value> for isize
• impl PartialEq<Value> for u8
• impl PartialEq<Value> for u16
• impl PartialEq<Value> for u32
• impl PartialEq<Value> for u64
• impl PartialEq<Value> for usize
• impl PartialEq<Value> for f32
• impl PartialEq<Value> for f64

These potentially lead to surprising inference errors in code that is unrelated to Serde: serde-rs/json#357, rust-lang/rust#46257

[ejpcmac]

Hello @dtolnay, I’ve come across some very strange type inference issues after adding a completely unrelated dependency to one of my projects, and just narrowed it down to serde_yaml. I have a minimal working example if it is helpful.

P.S. : The tricky thing was I did not add serde_yaml to my project, but probe-rs-rtt, which is using serde_yaml under the hood.