Fix extab splitting with -inline deferred

With `-inline deferred`, functions within a TU may be emitted in reverse order
in `.text`, while extab data remains in source (forward) order. This means
consecutive extabindex entries can reference decreasing extab addresses.
To avoid contradictory ordering constraints (which cause cyclic dependency errors
in link order resolution), we group such reversed entries and assign them a single
TU name, creating one covering split per section type.

Fixes #65
Fixes #120
Fixes #132

Author: encounter

src/util/dol.rs

@@ -1006,10 +1006,15 @@ fn locate_extab_extabindex(obj: &mut ObjInfo) -> Result<()> {
             )?;
         }
 
-        let mut entry_iter = eti_entries.iter().peekable();
+        // Sort by extab_addr for correct size computation.
+        // With -inline deferred, extab addresses may not be monotonically increasing
+        // in extabindex iteration order, so sorting ensures subtraction never underflows.
+        let mut sorted_entries: Vec<&EtiEntry> = eti_entries.iter().collect();
+        sorted_entries.sort_by_key(|e| e.extab_addr);
+        let mut entry_iter = sorted_entries.iter().peekable();
         loop {
             let (addr, size) = match (entry_iter.next(), entry_iter.peek()) {
-                (Some(a), Some(&b)) => (a.extab_addr, b.extab_addr - a.extab_addr),
+                (Some(a), Some(b)) => (a.extab_addr, b.extab_addr - a.extab_addr),
                 (Some(a), None) => (
                     a.extab_addr,
                     (extab_section_address + extab_section_size) as u32 - a.extab_addr,