[ELF] Group LTO options together. NFC.

[pcc]

LGTM

ELF/Options.td

 
 defm just_symbols: Eq<"just-symbols">, HelpText<"Just link symbols">;
 
 defm keep_unique: Eq<"keep-unique">, HelpText<"Do not fold this symbol during ICF">;
 
 defm library: Eq<"library">, HelpText<"Root name of library to use">,
   MetaVarName<"<libName>">;
 
-def lto_O: J<"lto-O">, MetaVarName<"<opt-level>">,
-  HelpText<"Optimization level for LTO">;
-
 def m: JoinedOrSeparate<["-"], "m">, HelpText<"Set target emulation">;
 
 defm Map: Eq<"Map">, HelpText<"Print a link map to the specified file">;
 
 defm merge_exidx_entries: B<"merge-exidx-entries",
     "Enable merging .ARM.exidx entries",
     "Disable merging .ARM.exidx entries">;
 

 def lto_aa_pipeline: J<"lto-aa-pipeline=">,
   HelpText<"AA pipeline to run during LTO. Used in conjunction with -lto-newpm-passes">;
 def lto_debug_pass_manager: F<"lto-debug-pass-manager">,
   HelpText<"Debug new pass manager">;
 def lto_new_pass_manager: F<"lto-new-pass-manager">,
   HelpText<"Use new pass manager">;
 def lto_newpm_passes: J<"lto-newpm-passes=">,
   HelpText<"Passes to run during LTO">;
+def lto_O: J<"lto-O">, MetaVarName<"<opt-level>">,
+  HelpText<"Optimization level for LTO">;
 def lto_partitions: J<"lto-partitions=">,
   HelpText<"Number of LTO codegen partitions">;
 def lto_sample_profile: J<"lto-sample-profile=">,
   HelpText<"Sample profile file path">;
 def disable_verify: F<"disable-verify">;
 defm mllvm: Eq<"mllvm">;
 def opt_remarks_filename: Separate<["--"], "opt-remarks-filename">,
   HelpText<"YAML output file for optimization remarks">;