extend docs of -Zprint-mono-items

Author: RalfJung

compiler/rustc_session/src/options.rs

@@ -1831,7 +1831,9 @@ options! {
  print_llvm_passes: bool = (false, parse_bool, [UNTRACKED],
  "print the LLVM optimization passes being run (default: no)"),
  print_mono_items: Option<String> = (None, parse_opt_string, [UNTRACKED],
- "print the result of the monomorphization collection pass"),
+ "print the result of the monomorphization collection pass. \
+ Value `lazy` means to use normal collection; `eager` means to collect all items.
+ Note that this overwrites the effect `-Clink-dead-code` has on collection!"),
  print_type_sizes: bool = (false, parse_bool, [UNTRACKED],
  "print layout information for each type encountered (default: no)"),
  print_vtable_sizes: bool = (false, parse_bool, [UNTRACKED],