[XRay] Make Trace loading endian-aware

This change makes the XRay Trace loading functions first use a
little-endian data extractor, then on failures try a big-endian data
extractor. Without this change, the trace loading facility will not work
with data written from a big-endian machine.

Follow-up to D51210 and D51289.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341226 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed