aot: const-owner handled string field reads cast to char *

[borisbat]

Follow-up to #3101. A string field read on a const handled owner emitted ((const char * const)(...)), which cannot flow into char * slots — das string always lowers to char * in AOT C++. So passing such a field directly as a function argument (e.g. equal(ann.name, "comment")) compiled interpreted but failed AOT C++ compilation. This was the only reproducible failure behind the "bound const char* field" concern; the lifetime side is theoretical post-#3101 (everything rtti-backed is context-lifetime).

Fix (daslib/aot_cpp.das, both the by-value and pointer-to-handle field paths): emit a two-step cast

((char *)(const char *)(owner.field))

• the inner (const char *) still picks the const-qualified conversion operator on class-typed members — the SimpleString case that motivated the const branch in f380818 (operator const char*() const is the only viable conversion on a const owner);
• the outer (char *) strips pointee-const at the pointer level, which is always valid there and safe because das strings are immutable.

Non-const owners keep the existing single (char *) cast.

With the wart gone, the "{x}" interpolation workarounds are reverted and double as regression coverage:

• tests/language/annotation_info.das — direct equal(ann.name, ...) / equal(arg.name, ...) passes (compiled by test_aot);
• modules/dasLLVM/daslib/llvm_jit.das — direct get_string_constant_ptr(g_builder, arg.name) etc. (compiled by the daslang -exe jit.exe build);
• ANNOTATION_INFO_REWORK.md wart section updated.

No codegen-version bump: the JIT change passes identical string content, generated code is unchanged.

Validation

• interpreted: annotation_info 6/6, simple_string 18/18
• AOT: full regen of every test with the new emitter (daslib glob dependency), suite 9406 tests — 9400 passed, 0 failed, 6 skipped (missing sf2 assets, pre-existing)
• JIT: jit_tests 293/293; annotation_info 6/6 under -jit -jit-no-cache; jit.exe built via daslang -exe and self-host-codegens annotation_info from a cold cache
• formatter --verify + lint clean on changed files

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR fixes an AOT C++ codegen constness mismatch for string field reads on const handled owners, where the emitter previously produced a const char*-qualified cast that could not flow into daScript’s AOT string representation (char *). It updates the AOT emitter to use a two-step cast that preserves the const-qualified conversion selection while still yielding char *, and removes workaround interpolations that existed solely to avoid the AOT compilation failure.

Changes:

• Update AOT C++ emitter to emit ((char *)(const char *)(...)) for const-owner handled string field reads (including pointer-to-handle field path).
• Revert string-interpolation workarounds in tests and LLVM JIT daslib code, using direct field passes as regression coverage.
• Update the rework/design doc to reflect the fix and remove the “interpolation required” guidance.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
daslib/aot_cpp.das	Adjusts generated C++ casts for const-owner handled string field reads to produce char * via a two-step cast.
tests/language/annotation_info.das	Removes interpolation workaround and asserts direct ann.name / arg.name usage (regression coverage for AOT).
modules/dasLLVM/daslib/llvm_jit.das	Removes interpolation workaround when building string constants from annotation fields so -exe builds don’t rely on formatting.
ANNOTATION_INFO_REWORK.md	Updates documentation to reflect that direct field passes now work in AOT; interpolation workaround no longer required.

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