[ARC] Handle complex PIC move patterns.

[ARC] Handle complex PIC move patterns.

fwprop step is placing in the REG_EQUIV notes constant pic unspecs
expressions.  Then, loop may use these notes for optimizations
rezulting in complex patterns that are not supported by the current
implementation.

The patch adds handling of complex PIC addresses having MINUS or UNARY
operations.

gcc/
2017-03-13  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (arc_legitimize_pic_address): Handle PIC
	expressions with MINUS and UNARY ops.

gcc/testsuite
2017-03-13  Claudiu Zissulescu  <claziss@synopsys.com>

	* gcc.target/arc/pr9001090948.c: New file.

From-SVN: r246087