Rollup merge of #136082 - Zalathar:iter-nodes, r=oli-obk

Incorporate `iter_nodes` into `graph::DirectedGraph`

This helper method iterates over all node IDs in the dense range `0..num_nodes`.

In practice, we have a lot of graph-algorithm code that already assumes that nodes are densely numbered, by using `num_nodes` to allocate per-node indexed data structures. So I don't think this is actually a substantial change to the de-facto semantics of `graph::DirectedGraph`.

---

Resolves a FIXME from #135481.

1 files changed, 0 insertions, 2 deletions

diff --git a/compiler/rustc_mir_transform/src/coverage/counters.rs b/compiler/rustc_mir_transform/src/coverage/counters.rs
index 50ebde3292e..adb99a75a9e 100644
--- a/compiler/rustc_mir_transform/src/coverage/counters.rs
+++ b/compiler/rustc_mir_transform/src/coverage/counters.rs
@@ -10,14 +10,12 @@ use rustc_index::bit_set::DenseBitSet;
 use rustc_middle::mir::coverage::{CounterId, CovTerm, Expression, ExpressionId, Op};
 
 use crate::coverage::counters::balanced_flow::BalancedFlowGraph;
-use crate::coverage::counters::iter_nodes::IterNodes;
 use crate::coverage::counters::node_flow::{
     CounterTerm, NodeCounters, make_node_counters, node_flow_data_for_balanced_graph,
 };
 use crate::coverage::graph::{BasicCoverageBlock, CoverageGraph};
 
 mod balanced_flow;
-mod iter_nodes;
 mod node_flow;
 mod union_find;