d: Merge upstream dmd 52844d4b1, druntime dbd0c874, phobos 896b1d0e1.

d: Merge upstream dmd 52844d4b1, druntime dbd0c874, phobos 896b1d0e1.

D front-end changes:

    - Parsing and compiling C code is now possible using `import'.
    - `throw' statements can now be used as an expression.
    - Improvements to the D template emission strategy when compiling
      with `-funittest'.

D Runtime changes:

    - New core.int128 module for implementing intrinsics to support
      128-bit integer types.
    - C bindings for the kernel and C runtime have been better separated
      to allow compiling for hybrid targets, such as kFreeBSD.

Phobos changes:

    - The std.experimental.checkedint module has been renamed to
      std.checkedint.

gcc/d/ChangeLog:

	* d-builtins.cc (d_build_builtins_module): Set purity of DECL_PURE_P
	functions to PURE::const_.
	* d-gimplify.cc (bit_field_ref): New function.
	(d_gimplify_modify_expr): Handle implicit casting for assignments to
	bit-fields.
	(d_gimplify_unary_expr): New function.
	(d_gimplify_binary_expr): New function.
	(d_gimplify_expr): Handle UNARY_CLASS_P and BINARY_CLASS_P.
	* d-target.cc (Target::_init): Initialize bitFieldStyle.
	(TargetCPP::parameterType): Update signature.
	(Target::supportsLinkerDirective): New function.
	* dmd/MERGE: Merge upstream dmd 52844d4b1.
	* expr.cc (ExprVisitor::visit (ThrowExp *)): New function.
	* types.cc (d_build_bitfield_integer_type): New function.
	(insert_aggregate_bitfield): New function.
	(layout_aggregate_members): Handle inserting bit-fields into an
	aggregate type.

libphobos/ChangeLog:

	* Makefile.in: Regenerate.
	* libdruntime/MERGE: Merge upstream druntime dbd0c874.
	* libdruntime/Makefile.am (DRUNTIME_CSOURCES): Add core/int128.d.
	(DRUNTIME_DISOURCES): Add __builtins.di.
	* libdruntime/Makefile.in: Regenerate.
	* src/MERGE: Merge upstream phobos 896b1d0e1.
	* src/Makefile.am (PHOBOS_DSOURCES): Add std/checkedint.d.
	* src/Makefile.in: Regenerate.
	* testsuite/testsuite_flags.in: Add -fall-instantiations to
	--gdcflags.