minor fixes

- copy alt name to config arena
- promote alternate name conflict error to stop run
- remove unused error code

src/linker/lnk_config.c

@@ -1060,6 +1060,8 @@ lnk_apply_cmd_option_to_config(Arena *arena, LNK_Config *config, String8 cmd_nam
     if (value_strings.node_count == 1) {
       LNK_AltName alt_name;
       if (lnk_parse_alt_name_directive(value_strings.first->string, &alt_name)) {
+        alt_name.from = push_str8_copy(arena, alt_name.from);
+        alt_name.to = push_str8_copy(arena, alt_name.to);
         LNK_AltNameNode *alt_name_n = push_array(arena, LNK_AltNameNode, 1);
         alt_name_n->data = alt_name;
         SLLQueuePush(config->alt_name_list.first, config->alt_name_list.last, alt_name_n);

src/linker/lnk_error.h

@@ -39,18 +39,17 @@ typedef enum
   LNK_Error_CircularMerge,
   LNK_Error_UnresolvedSymbol,
   LNK_Error_AssociativeLoop,
+  LNK_Error_AlternateNameConflict,
   LNK_Error_StopLast,
   
   LNK_Error_First,
   LNK_Error_AlreadyDefinedSymbol,
-  LNK_Error_AlternateNameConflict,
   LNK_Error_CvPrecomp,
   LNK_Error_Natvis,
   LNK_Error_TooManyFiles,
   LNK_Error_UnableToOpenTypeServer,
   LNK_Error_UnexpectedCodePath,
   LNK_Error_CvIllSymbolData,
-  LNK_Error_IllegalAlternateNameRedifine,
   LNK_Error_InvalidTypeIndex,
   LNK_Error_UndefinedIsWeak,
   LNK_Error_WeakCycle,