gcc/

	PR rtl-optimization/52876
	* emit-rtl.c (set_reg_attrs_from_value): Handle arbitrary value.
	Don't call mark_reg_pointer for incompatible pointer sign
	extension.

	* reginfo.c (reg_scan_mark_refs): Call set_reg_attrs_from_value 
	directly.

gcc/testsuite

	PR rtl-optimization/52876
	* gcc.target/i386/pr52876.c: New.

From-SVN: r186351