ANN: check #[deprecated] attr syntax: E0538, E0551, E0541

[kuksag]

changelog:

• Add support for E0538, multiple items used in #[deprecated] attribute, e.g.:

#[deprecated(
    since = "a",
    since = "b", // error
    note = "c"
)]
fn f1() { }

Error code reference: https://doc.rust-lang.org/error_codes/E0538.html
Compiler reference: https://github.com/rust-lang/rust/blob/904dd2c3987028f0270db306b9964bc465689de8/compiler/rustc_attr/src/builtin.rs#L834

• Add support for E0541, unknown item used inside #[deprecated]:

#[deprecated(
    since="1.0.0",
    // error: unknown meta item
    reason="Example invalid meta item. Should be 'note'")
]
fn deprecated_function() {}

Error code reference: https://doc.rust-lang.org/error_codes/E0541.html
Compiler reference: https://github.com/rust-lang/rust/blob/904dd2c3987028f0270db306b9964bc465689de8/compiler/rustc_attr/src/builtin.rs#L891

• Add support for E0551, invalid item was used (key-value param expected):

#[deprecated(note)] // error!
fn i_am_deprecated() {}

Error code reference: https://doc.rust-lang.org/error_codes/E0551.html
Compiler reference:
https://github.com/rust-lang/rust/blob/904dd2c3987028f0270db306b9964bc465689de8/compiler/rustc_attr/src/builtin.rs#L852

• Add tests for quick-fixes

[Undin]

@kuksag let's avoid merging master branch into feature branch. Use rebase, please

[vlad20012]

bors r+

[bors]

Build succeeded:

• check