lintcheck: Add JSON output, diff subcommand

[Alexendoo]

This adds a JSON output to lintcheck, cargo lintcheck --json ... will create a JSON file that is the serialisation of the Vec<ClippyWarning> results

cargo lintcheck diff a.json b.json can then be used to show the difference between two runs

Moves the path rewriting to --remap-path-prefix in order to have it reflected in the rendered diagnostics

changelog: none

[rust-highfive]

r? @giraffate

(rust-highfive has picked a reviewer for you, use r? to override)

[Alexendoo]

r? @matthiaskrgr (whoops, forgot to do that)

Here's an example output for the diff of running cargo lintcheck --recursive --json before/after #9743:

35 added, 0 removed, 136 changed

Added

warning: the following explicit lifetimes could be elided: 'a
   --> serde_derive-1.0.123/src/ser.rs:869:1
    |
869 | / fn serialize_struct_variant<'a>(
870 | |     context: StructVariant<'a>,
871 | |     params: &Parameters,
872 | |     fields: &[Field],
873 | |     name: &str,
874 | | ) -> Fragment {
    | |_____________^
    |
help: replace with `'_` in generic arguments such as here
   --> serde_derive-1.0.123/src/ser.rs:870:28
    |
870 |     context: StructVariant<'a>,
    |                            ^^
    = note: `#[warn(clippy::needless_lifetimes)]` implied by `#[warn(clippy::all)]`

warning: the following explicit lifetimes could be elided: 'a
   --> serde_derive-1.0.110/src/ser.rs:865:1
    |
865 | / fn serialize_struct_variant<'a>(
866 | |     context: StructVariant<'a>,
867 | |     params: &Parameters,
868 | |     fields: &[Field],
869 | |     name: &str,
870 | | ) -> Fragment {
    | |_____________^
    |
help: replace with `'_` in generic arguments such as here
   --> serde_derive-1.0.110/src/ser.rs:866:28
    |
866 |     context: StructVariant<'a>,
    |                            ^^
    = note: `#[warn(clippy::needless_lifetimes)]` implied by `#[warn(clippy::all)]`

[ trimmed ]

Changed

-warning: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
+warning: the following explicit lifetimes could be elided: 'a
   --> bstr-0.2.17/src/ext_slice.rs:70:1
    |
 70 | pub fn B<'a, B: ?Sized + AsRef<[u8]>>(bytes: &'a B) -> &'a [u8] {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(clippy::needless_lifetimes)]` on by default
 
 
-warning: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
+warning: the following explicit lifetimes could be elided: 'r
     --> regex-1.4.3/src/re_bytes.rs:1168:5
      |
 1168 |     fn no_expansion<'r>(&'r mut self) -> Option<Cow<'r, [u8]>> {
      |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+     |
+help: replace with `'_` in generic arguments such as here
+    --> regex-1.4.3/src/re_bytes.rs:1168:53
+     |
+1168 |     fn no_expansion<'r>(&'r mut self) -> Option<Cow<'r, [u8]>> {
+     |                                                     ^^
 
[ trimmed ]

[bors]

☔ The latest upstream changes (presumably #9945) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #10356) made this pull request unmergeable. Please resolve the merge conflicts.

[Alexendoo]

Superseded by #10398