Rollup merge of #126567 - compiler-errors:instance-kind, r=oli-obk,lcnr

Rename `InstanceDef` -> `InstanceKind`

Renames `InstanceDef` to `InstanceKind`. The `Def` here is confusing, and makes it hard to distinguish `Instance` and `InstanceDef`. `InstanceKind` makes this more obvious, since it's really just describing what *kind* of instance we have.

Not sure if this is large enough to warrant a types team MCP -- it's only 53 files. I don't personally think it does, but happy to write one if anyone disagrees. cc ``@rust-lang/types``

r? types

compiler/rustc_mir_transform/src/coverage/query.rs

@@ -49,7 +49,7 @@ fn is_eligible_for_coverage(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
 /// Query implementation for `coverage_ids_info`.
 fn coverage_ids_info<'tcx>(
     tcx: TyCtxt<'tcx>,
-    instance_def: ty::InstanceDef<'tcx>,
+    instance_def: ty::InstanceKind<'tcx>,
 ) -> CoverageIdsInfo {
     let mir_body = tcx.instance_mir(instance_def);