[PATCH, PPC 2/2] Fix Darwin bootstrap after split of rs6000.c.

[PATCH, PPC 2/2] Fix Darwin bootstrap after split of rs6000.c.

To fix this we need to make the branch islands (or code) visible between
both files.  This keeps the generation side in rs6000.c and moves the
output routine to rs6000-logue.c, placing a reference to the islands
vector in rs6000-internal.h.

2019-06-26  Iain Sandoe  <iain@sandoe.co.uk>

	* config/rs6000/rs6000-internal.h (branch_island): New typedef.
	(branch_islands): New extern.
	* config/rs6000/rs6000-logue.c (macho_branch_islands): Moved from
	* config/rs6000/rs6000.c: .. here.

From-SVN: r272710