[ARC] Fix legitimize pic address.

[ARC] Fix legitimize pic address.

There are cases when an pic address gets complicated, and it needs to
be resolved via force_reg function found in
prepare_move_operands. When this happens, we need to disambiguate the
pic address and re-legitimize it.

gcc/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (arc_legitimize_pic_address): Consider UNSPECs
	as well, if interesting recover the symbol and re-legitimize the
	pic address.

gcc/testsuite/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* gcc.target/arc/pic-2.c: New file.

From-SVN: r278056