Revert "Put r184469 disassembler test back on X86"

This reverts commit r184602. In an upcoming commit, I will just remove
the disassembler part of the test; it was mostly just a "nifty" thing
marking a milestone but it doesn't test anything that isn't tested
elsewhere.
This was a nifty test, but remove it.

It wouldn't really test anything that doesn't already have a more
targeted test:
`yaml2obj-elf-section-basic.yaml`:
  Already tests that section content is correctly passed though.
`yaml2obj-elf-symbol-basic.yaml` (this file):
  Tests that the st_value and st_size attributes of `main` are set
  correctly.
Between those two tests, disassembling the file doesn't really add
anything, so just remove mention of disassembling the file.