* lib/gas-defs.exp (run_dump_test): Support new attribute "stderr"
which is a file used to regexp_diff the assembler's pruned stderr
output.
(write_file): New helper function to write a string into a file.
* gas/mips/empic.l: New file which matches empic tests' warnings.
* gas/mips/empic.d: Use empic.l.
indeterminate number of extra lines here".
* gas/elf/elf.exp: Remove XFAILs.
* gas/elf/section0.d: Make pass on MIPS (and hopefully alpha).
* gas/elf/section1.d: Likewise.
