[flang] clean up comments, put out for review

Original-commit: flang-compiler/f18@26a3221fc4
Reviewed-on: https://github.com/flang-compiler/f18/pull/219
Tree-same-pre-rewrite: false

flang/lib/evaluate/call.h

@@ -45,7 +45,6 @@ struct ActualArgument {
   bool isAlternateReturn{false};  // when true, "value" is a label number
 
   // TODO: Mark legacy %VAL and %REF arguments
-  // TODO: pmk: Mark arguments that were originally parenthesized
 
   // Subtlety: There is a distinction that must be maintained here between an
   // actual argument expression that is a variable and one that is not,

flang/lib/evaluate/tools.h

@@ -110,7 +110,7 @@ std::optional<std::int64_t> ToInt64(const std::optional<A> &x) {
   }
 }
 
-// TODO pmk: GetSymbol and Rank and GetType here, too
+// TODO: GetSymbol and Rank and GetType here, too
 
 // Generalizing packagers: these take operations and expressions of more
 // specific types and wrap them in Expr<> containers of more abstract types.