Auto merge of #119459 - cjgillot:inline-mir-utils, r=compiler-errors

Inline a few utility functions around MIR

Most of them are small enough to benefit from inlining.

compiler/rustc_data_structures/src/graph/dominators/mod.rs

@@ -394,6 +394,7 @@ impl<Node: Idx> Dominators<Node> {
     /// # Panics
     ///
     /// Panics if `b` is unreachable.
+    #[inline]
     pub fn dominates(&self, a: Node, b: Node) -> bool {
         match &self.kind {
             Kind::Path => a.index() <= b.index(),