ELF: improve CIE no-augmentation test

Add another possible error that may be reported for the same case. The
original reproduction case that prompted r270706 produced the error
"corrupted CIE" instead of "corrupted or unsupported CIE information".
The specific error depends on arbitrary data later in the file so
check that neither is emitted in case the input is ever changed.

Document the process used to create the input .o and rename the test
file to .s, as requested by Rafael.

llvm-svn: 270709