proposal. This leaves the strings in the skeleton die as strp,
but in all dwo files they're accessed now via DW_FORM_GNU_str_index.

Add support for dumping these sections and modify the fission-cu.ll
testcase to have the correct strings and form. Fix a small bug
in the fixed form sizes routine that involved out of array accesses
for the table and add a FIXME in the extractFast routine to fix
this up.

llvm-svn: 171779