[llvm] [llvm-objcopy] Improve help messages (PR #82830)

[Ilia Kuklin via llvm-commits]

================
@@ -49,17 +46,15 @@ defm add_gnu_debuglink
 
 defm rename_section
     : Eq<"rename-section",
-         "Renames a section from old to new, optionally with specified flags. "
-         "Flags supported for GNU compatibility: alloc, load, noload, "
-         "readonly, exclude, debug, code, data, rom, share, contents, merge, "
-         "strings, large">,
+         "Rename sections called <old> to <new>, and apply any specified <flag> values. "
+         "See --set-section-flags for a list of supported flags">,
       MetaVarName<"old=new[,flag1,...]">;
 defm redefine_symbol
     : Eq<"redefine-sym", "Change the name of a symbol old to new">,
       MetaVarName<"old=new">;
 defm redefine_symbols
     : Eq<"redefine-syms",
-         "Reads a list of symbol pairs from <filename> and runs as if "
+         "Read a list of symbol pairs from <filename> and runs as if "
----------------
kuilpd wrote:

```suggestion
         "Read a list of symbol pairs from <filename> and run as if "
```

https://github.com/llvm/llvm-project/pull/82830