Unwind plan augmentation should compute the plan row at offset x from
the instruction before offset x, but currently we compute it from the
instruction at offset x. Note that this behavior is a regression
introduced when moving the x86 assembly inspection engine to its own
file
(1c9858b298 (diff-375a2be066db6f34bb9a71442c9b71fcL913));
the original version handled this properly by copying the previous
instruction out before advancing the instruction pointer.
The relevant bug with more info is here: https://bugs.llvm.org/show_bug.cgi?id=43561
Differential Revision: https://reviews.llvm.org/D68454
Patch by Jaroslav Sevcik <jarin@google.com>.
llvm-svn: 374342