[nanvix] E: Phase 1C — build 8 Tier-1 text-codec modules as .so

Phase 1C of the .a -> .so migration (see
nanvix-todo/cpython-static-to-shared-migration.md section 5).
Builds on Phase 1B (#6, #7) by promoting the remaining 8 Tier-1
"text codec" stdlib extension modules from statically linked into
python.elf to dlopen-loaded shared objects under
lib/python3.12/lib-dynload/.

Modules moved to *shared* in Modules/Setup.local generation
(.nanvix/docker.py):

- unicodedata: Unicode database lookups (the big one — 1.2 MB of
  unicode data tables).
- _multibytecodec: shared CJK codec infrastructure.
- _codecs_cn / _codecs_hk / _codecs_iso2022 / _codecs_jp /
  _codecs_kr / _codecs_tw: per-region CJK codec tables.

None of the eight reference external libraries; they are pure C
with embedded data tables. They link against the same -lc /
runtime symbols that the rest of the Phase 1 modules use.

Test coverage (.nanvix/test.py):

- New phase1c_snippet imports each module, asserts it is NOT in
  sys.builtin_module_names, exercises one trivial API call to
  confirm dlopen + PyInit_<name> succeeded (unicodedata.lookup,
  _multibytecodec.__create_codec, _codecs_<region>.getcodec), and
  prints the resolved __file__ path. Phase 1A/1B probes retained.

Validation on local toolchain (phase0-llfix):

- All 8 new .so files produced and installed under lib-dynload/
  (unicodedata 1193K, _codecs_jp 262K, _codecs_hk 168K,
  _codecs_cn 155K, _codecs_kr 145K, _multibytecodec 147K,
  _codecs_tw 115K, _codecs_iso2022 76K — total ~2.2 MB across
  the eight files).
- nm python.elf no longer shows PyInit_<name> for any of the 8.
- python.elf size: 19.18 MB (Phase 1B) -> 17.48 MB (Phase 1C),
  -1.70 MB. Biggest single-phase reduction so far because the
  CJK codec tables and the Unicode database are large.
- Hello + Phase 1A + Phase 1B + Phase 1C import probes + lxml +
  HTTP smoke + full regrtest 160/160 PASS in standalone mode.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Enrique Saurez

.nanvix/docker.py

@@ -320,6 +320,15 @@ def _generate_setup_local_cmd() -> str:
         f"'_statistics _statisticsmodule.c' "
         f"'mmap mmapmodule.c' "
         f"'_contextvars _contextvarsmodule.c' "
+        f"'# Phase 1C: Tier-1 text codecs (pure C, no external deps).' "
+        f"'unicodedata unicodedata.c' "
+        f"'_multibytecodec cjkcodecs/multibytecodec.c' "
+        f"'_codecs_cn cjkcodecs/_codecs_cn.c' "
+        f"'_codecs_hk cjkcodecs/_codecs_hk.c' "
+        f"'_codecs_iso2022 cjkcodecs/_codecs_iso2022.c' "
+        f"'_codecs_jp cjkcodecs/_codecs_jp.c' "
+        f"'_codecs_kr cjkcodecs/_codecs_kr.c' "
+        f"'_codecs_tw cjkcodecs/_codecs_tw.c' "
         f"> {ws}/Modules/Setup.local"
     )
 

.nanvix/test.py

@@ -488,6 +488,27 @@ def stage(
         "    print(f'CPYTHON_TEST_PHASE1A: {_name} loaded via dlopen from "
         "{_mod.__file__}')\n"
     )
+    # Phase 1C: Tier-1 text-codec modules (CJK + unicodedata). No
+    # external deps; resolve against python.elf's .dynsym via dlopen.
+    phase1c_snippet = (
+        "_phase1c = [\n"
+        "    ('unicodedata', lambda m: m.lookup('LATIN SMALL LETTER A') == 'a'),\n"
+        "    ('_multibytecodec', lambda m: hasattr(m, '__create_codec')),\n"
+        "    ('_codecs_cn', lambda m: hasattr(m, 'getcodec')),\n"
+        "    ('_codecs_hk', lambda m: hasattr(m, 'getcodec')),\n"
+        "    ('_codecs_iso2022', lambda m: hasattr(m, 'getcodec')),\n"
+        "    ('_codecs_jp', lambda m: hasattr(m, 'getcodec')),\n"
+        "    ('_codecs_kr', lambda m: hasattr(m, 'getcodec')),\n"
+        "    ('_codecs_tw', lambda m: hasattr(m, 'getcodec')),\n"
+        "]\n"
+        "for _name, _check in _phase1c:\n"
+        "    _mod = __import__(_name)\n"
+        "    assert _name not in sys.builtin_module_names, "
+        "f'{_name} still built-in!'\n"
+        "    assert _check(_mod), f'{_name} sanity check failed'\n"
+        "    print(f'CPYTHON_TEST_PHASE1C: {_name} loaded via dlopen from "
+        "{_mod.__file__}')\n"
+    )
     # Phase 1B: Tier-1 math + memory modules. Same dlopen flow; libm
     # symbols are pulled from python.elf via --whole-archive.
     phase1b_snippet = (
@@ -526,6 +547,7 @@ def stage(
         + array_snippet
         + phase1a_snippet
         + phase1b_snippet
+        + phase1c_snippet
         + (lxml_snippet if standalone else ""),
     )