re PR rtl-optimization/44787 (internal compiler error: in reload_cse_simplify_operands, at postreload.c:395)

	PR rtl-optimization/44787
	* config/arm/arm.md (arith_shiftsi): Allow stack pointer in operand 2.
	* config/arm/thumb2.md (thumb2_arith_shiftsi): Likewise.

testsuite/
	PR rtl-optimization/44787
	* gcc.c-torture/compile/pr44788.c: New test.
	* gcc.target/arm/pr44788.c: New test.

From-SVN: r161893