[llvm-gsymutil] Fix command descriptions introduced in upstream D148775 when switching to OptTable

[kusmour]

Summary

D148775 changed the help msg for --addresses-from-stdin option when switching to OptTable

This patch also fixed a small problem in the argument type error msg

[kusmour]

rebase on to latest upstream

[clayborg]

lgtm

llvm/tools/llvm-gsymutil/Opts.td

Eq<"num-threads",
      "Specify the maximum number (n) of simultaneous threads to use when converting files to GSYM.\nDefaults to the number of cores on the current machine">;
 defm segment_size :
   Eq<"segment-size",
      "Specify the size in bytes of the size the final GSYM file should be segmented into. This allows GSYM files to be split across multiple files">;
 def quiet : FF<"quiet", "Do not output warnings about the debug information">;
 defm address : Eq<"address", "Lookup an address in a GSYM file">;
 def addresses_from_stdin :
   FF<"addresses-from-stdin",
-     "Emit a section containing remark diagnostics metadata. By default, this is enabled for the following formats: yaml-strtab, bitstream">;
+     "Lookup addresses in a GSYM file that are read from stdin\nEach input line is expected to be of the following format: <addr> <gsym-path>">;

llvm/tools/llvm-gsymutil/llvm-gsymutil.cpp

if (const llvm::opt::Arg *A = Args.getLastArg(OPT_segment_size_EQ)) {
     }
   }
 
   Quiet = Args.hasArg(OPT_quiet);
 
   for (const llvm::opt::Arg *A : Args.filtered(OPT_address_EQ)) {
     StringRef S{A->getValue()};
     if (!llvm::to_integer(S, LookupAddresses.emplace_back(), 0)) {
-      llvm::errs() << ToolName << ": for the --segment-size option: '" << S
+      llvm::errs() << ToolName << ": for the --address option: '" << S
                    << "' value invalid for uint argument!\n";
       std::exit(1);
     }
   }
 
   LookupAddressesFromStdin = Args.hasArg(OPT_addresses_from_stdin);
 }