Move tests from `tests/ui/issues/` to appropriate directories In this PR, I am moving the following test from `tests/ui/issues` directory to the appropriate directories, followed by the addition of issue links at the top and reblessing of the stderr files: | old-name | new-sub-dir | new-name | |-|-|-| | `issue-29516.rs` | `auto-traits/` | `distinct-type-tuple-by-negative-impl.rs` | | `issue-3874.rs` | `binding/` | `ref-in-let-lhs-in-field.rs` | | `issue-32782.rs` | `feature-gates/` | `feature-gate-check-nested-macro-invocation.rs` | | `issue-32782.stderr` | `feature-gates/` | `feature-gate-check-nested-macro-invocation.stderr` | | `issue-5100.rs` | `pattern/` | `match-errors-derived-error-suppression.rs` | | `issue-5100.stderr` | `pattern/` | `match-errors-derived-error-suppression.stderr` | | `issue-21033.rs` | `pattern/` | `match-struct-var-having-boxed-field.rs` | r? Kivooeo r? Teapot4195