[Darwin, machopic 3/n] Set a SYMBOL flag for indirections.

[Darwin, machopic 3/n] Set a SYMBOL flag for indirections.

We are able to treat these specially where needed in legitimate address
tests (specifically, they are guaranteed to be pointer-aligned).

gcc/ChangeLog:

2019-10-09  Iain Sandoe  <iain@sandoe.co.uk>

	* config/darwin.c (machopic_indirect_data_reference): Set flag to
	indicate that the new symbol is an indirection.
	(machopic_indirect_call_target): Likewise.
	* config/darwin.h (MACHO_SYMBOL_FLAG_INDIRECTION): New.
	(MACHO_SYMBOL_INDIRECTION_P): New.
	(MACHO_SYMBOL_FLAG_STATIC): Adjust bit number.

From-SVN: r276767