Fail gracefully on symbols with an invalid section name

src/symbol_table.rs

@@ -73,7 +73,7 @@ impl SymbolTable {
             .map(|sym| {
                 (
                     symstrtab.get(sym.st_name as usize).unwrap().to_string(),
-                    Symbol::new(&sym, sect_names[sym.st_shndx as usize].to_string()),
+                    Symbol::new(&sym, sect_names.get(sym.st_shndx as usize).map_or_else(|| "UNKNOWN".to_string(), |x| x.to_string())),
                 )
             })
             .collect::<HashMap<_, _>>();