* arm.cc (Arm_output_section::Arm_output_section): Set SHF_LINK_ORDER
flag of a SHT_ARM_EXIDX section.
* testsuite/Makefile.am (arm_exidx_test): New test rules.
* testsuite/Makefile.in: Regenerate.
* testsuite/arm_exidx_test.s: New file.
* testsuite/arm_exidx_test.sh: Same.