(LEGITIMATE_CONSTANT_P, LEGITIMATE_PIC_OPERAND_P): Use
LEGITIMATE_PIC_OPERAND_P, not LEGITIMATE_CONSTANT_P,
to set current_function_uses_pic_offset_table.
(INDIRECTABLE_1_ADDRESS_P): Baseregisters are not legal
for {LABEL,SYMBOL}_REFS when emitting pic.
(GO_IF_INDEXABLE_ADDRESS): INDIRECTABLE_1_ADDRESSes are indexable too.

From-SVN: r6926