build,qt: Decouple generation of moc files
* m4/qt5.m4: Export moc for Qt 5 in variable MOC5. Unset temporary MOC2. * m4/qt6.m4: Export moc for Qt 6 in variable MOC6. * lang/qt/src/Makefile.am: Generate .moc5 files from .h files. Generate .moc forwarding headers in moc5 subfolder. Add moc5 subfolder to include paths for Qt 5-based qgpgme library. Ditto for Qt 6. Clean up moc5 and moc6 subfolders. * lang/qt/tests/Makefile.am: List tests and test runners for Qt 5 and Qt 6. Generate .moc5 files from .cpp files of tests. Generate .moc forwarding headers in moc5 subfolder. Generate .hmoc file from t-support.h directly in moc5 subfolder. Add moc5 subfolder to include paths for all Qt 5-based tests and runners. Ditto for Qt 6. Specify sources, LDADD and CPPFLAGS for all tests and test runners for Qt 5 and Qt 6. Clean up moc5 and moc6 subfolders.
The output of Qt 5's moc and Qt 6's moc is incompatible. Therefore, we
need to generate different .moc files for Qt 5 and Qt 6 to support
co-building of the Qt 5 and Qt 6 bindings. The duplication of the
listing of the tests couldn't be avoided because automake doesn't
understand the_tests5 = $(the_tests:%=%5) and couldn't match the
tests with their _SOURCES. Maybe some m4 programming would have helped,
but that would have made the Makefiles even more unreadable.
- GnuPG-bug-id: T7205