Apply suggestions from code review

Co-authored-by: Wesley Wiser <wwiser@gmail.com>

Author: oli-obk

src/librustc_middle/mir/mod.rs

@@ -77,14 +77,14 @@ impl<'tcx> HasLocalDecls<'tcx> for Body<'tcx> {
 /// dialects forbid certain variants or values in certain phases.
 ///
 /// Note: Each phase's validation checks all invariants of the *previous* phases' dialects. A phase
-/// that changes the dialect documents what invariants must be uphelpd *after* that phase finishes.
+/// that changes the dialect documents what invariants must be upheld *after* that phase finishes.
 ///
 /// Warning: ordering of variants is significant.
 #[derive(Copy, Clone, TyEncodable, TyDecodable, Debug, PartialEq, Eq, PartialOrd, Ord)]
 #[derive(HashStable)]
 pub enum MirPhase {
     Build = 0,
-    // FIXME: it's unclear whether we still need this phase (and its corresponding query).
+    // FIXME(oli-obk): it's unclear whether we still need this phase (and its corresponding query).
     // We used to have this for pre-miri MIR based const eval.
     Const = 1,
     /// This phase checks the MIR for promotable elements and takes them out of the main MIR body

src/librustc_mir/transform/const_prop.rs

@@ -857,7 +857,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
 
                             if let Some(Some(alloc)) = alloc {
                                 // Assign entire constant in a single statement.
-                                // We can't use aggregates, as we are post-aggregate-lowering.
+                                // We can't use aggregates, as we run after the aggregate-lowering `MirPhase`.
                                 *rval = Rvalue::Use(Operand::Constant(Box::new(Constant {
                                     span: source_info.span,
                                     user_ty: None,