d: Merge upstream dmd 821ed393d, druntime 454471d8, phobos 1206fc94f.

D front-end changes:

    - Import latest bug fixes to mainline.

D runtime changes:

    - Fix duplicate Elf64_Dyn definitions on Solaris.
    - _d_newThrowable has been converted to a template.

Phobos changes:

    - Import latest bug fixes to mainline.

gcc/d/ChangeLog:

	* dmd/MERGE: Merge upstream dmd 821ed393d.
	* expr.cc (ExprVisitor::visit (NewExp *)): Remove handled of
	allocating `@nogc' throwable object.
	* runtime.def (NEWTHROW): Remove.

libphobos/ChangeLog:

	* libdruntime/MERGE: Merge upstream druntime 454471d8.
	* libdruntime/Makefile.am (DRUNTIME_DSOURCES): Add
	core/sync/package.d.
	* libdruntime/Makefile.in: Regenerate.
	* src/MERGE: Merge upstream phobos 1206fc94f.