[qt/clang/llvm]: Summary of bulk changes made

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/users/makslevental/mlir-c-typeconverter-materialization'.
Changed from 0747c994b3badf2322f7af5362ceb9556e3f42ec to 4c716e5e3934ff57b593aa33374bd4438c34e793
Acknowledgement was received that this change introduces only existing code that has been pushed to another public open source repository.

This change contains the following new commits:

Git commit 4c716e5e3934ff57b593aa33374bd4438c34e793 by makslevental on 21/07/2026 at 19:38..
[mlir-c] Use a tri-state status enum for the type conversion callback

MlirTypeConverterConversionCallback returned MlirLogicalResult and used a
null convertedType as a second failure sentinel, which could only express
success or "try another conversion" -- and conflated the C++ decline
(std::nullopt) and hard-failure (failure()) states.

Introduce MlirTypeConverterConversionStatus (Success/Failure/Declined) and
return it from the callback instead, mapping the three states to success(),
failure(), and std::nullopt respectively. Update the Python binding and the
C API test callback accordingly.

Add a C API unit test (testTypeConverterConversionStatus) exercising all
three status values through mlirTypeConverterConvertType.
https://invent.kde.org/qt/clang/llvm/-/commit/4c716e5e3934ff57b593aa33374bd4438c34e793