prefix.h: Wrap up in extern "C" block.

prefix.h: Wrap up in extern "C" block.

	* prefix.h: Wrap up in extern "C" block.
ada/
	* adadecode.c: Wrap up in extern "C" block.
	* adadecode.h: Likewise.
	* adaint.c: Likewise.  Remove 'const' keyword.
	* adaint.h: Likewise.
	* argv.c: Likewise.
	* atree.h: Likewise.
	* cio.c: Likewise.
	* cstreams.c: Likewise.
	* env.c: Likewise.
	* exit.c: Likewise.
	* fe.h: Likewise.
	* final.c: Likewise.
	* init.c: Likewise.
	* initialize.c: Likewise.
	* link.c: Likewise.
	* namet.h: Likewise.
	* nlists.h: Likewise.
	* raise.c: Likewise.
	* raise.h: Likewise.
	* repinfo.h: Likewise.
	* seh_init.c: Likewise.
	* targext.c: Likewise.
	* tracebak.c: Likewise.
	* uintp.h: Likewise.
	* urealp.h: Likewise.
	* xeinfo.adb: Wrap up generated C code in extern "C" block.
	* xsinfo.adb: Likewise.
	* xsnamest.adb: Likewise.
	* gcc-interface/gadaint.h: Wrap up in extern "C" block.
	* gcc-interface/gigi.h: Wrap up some prototypes in extern "C" block.
	* gcc-interface/misc.c: Likewise.
	* gcc-interface/Make-lang.in (GCC_LINK): Use LINKER.
	(GNAT1_C_OBJS): Remove ada/b_gnat1.o.  List ada/seh_init.o and
	ada/targext.o here...
	(GNAT_ADA_OBJS): ...and not here.
	(GNAT1_ADA_OBJS): Add ada/b_gnat1.o.
	(GNATBIND_OBJS): Reorder.

Co-Authored-By: Eric Botcazou <ebotcazou@adacore.com>
From-SVN: r176210