d: Merge upstream dmd, druntime f1a045928e

D front-end changes:

    - Import dmd v2.106.1-rc.1.
    - Unrecognized pragmas are no longer an error by default.

D runtime changes:

    - Import druntime v2.106.1-rc.1.

gcc/d/ChangeLog:

	* dmd/MERGE: Merge upstream dmd f1a045928e.
	* dmd/VERSION: Bump version to v2.106.1-rc.1.
	* gdc.texi (fignore-unknown-pragmas): Update documentation.
	* d-builtins.cc (covariant_with_builtin_type_p): Update for new
	front-end interface.
	* d-lang.cc (d_parse_file): Likewise.
	* typeinfo.cc (make_frontend_typeinfo): Likewise.

libphobos/ChangeLog:

	* libdruntime/MERGE: Merge upstream druntime f1a045928e.
	* libdruntime/Makefile.am (DRUNTIME_DSOURCES): Add
	core/stdc/stdatomic.d.
	* libdruntime/Makefile.in: Regenerate.