[lto] Spurious failures in lto tests with -jN

[Diego Novillo]

I've noticed some spurious failures in the lto tests (g++.dg/lto and
gcc.dg/lto).  They only occur with -jN.  The symptom is an error
message from ld complaining that a .lto.ltrans.o file is missing.  I
think this is a bug in the lto.exp script because the tests work fine
with -j1.

I'll be taking a look to see if I can fix this.  In the meantime, if
you get weird errors, try running the failing tests cases with -j1.


Thanks.  Diego.