re PR target/37436 (arm-cross-g++. internal compiler error: in extract_insn, at recog.c:1990)
PR target/37436
* arm.c (arm_legitimate_index): Only accept addresses that are in
canonical form.
* predicates.md (arm_reg_or_extendqisi_mem_op): New predicate.
* arm.md (extendqihi2): Use arm_reg_or_extendqisi_mem_op predicate
for operand1.
(extendqisi2): Likewise.
(arm_extendqisi, arm_extendqisi_v6): Use arm_extendqisi_mem_op
predicate for operand1.