Reorder mangleProcNameExt and makeUnique so the module suffix comes LAST:
name_u<disamb>__<suffix> (was name__<suffix>_u<disamb>). The suffix is now a
strippable trailing token, so content-addressed cross-module merging (the
per-module backend's instance/hook dedup) can recover a mint-site-independent
name by chopping everything from the final "__" -- no reference rewriting.
Also drops the main-module special case in mangleProcNameExt: it omitted the
suffix because the main module's symbols key on its NIF-suffix file index. But
the backend already aliases that suffix to the main's source index
(nifbackend.loadModuleDependencies), so graph.ifaces[s.itemId.module] is
populated for the main module too -- the guard was redundant. Main-module
procs now mangle uniformly (e.g. mainProc_u0__<mainname>).
icFormatVersion 3 -> 4: cached .c.nif artifacts hold the old name scheme and
must be wiped.
Validated: koch boot (non-IC self-host) reaches fixed point; koch ic thallo
tconverter timp tmiscs tparseutils all green; a 3-module diamond IC build
runs correctly.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
the function name extension encoded by paths could be useful for
debugging where the function is from
Before:
```js
function newSeq_33556909(len_33556911)
```
After:
```js
function newSeq__system_u2477(len_p0)
```
