use the very-handy getTruncateOrZeroExtend helper function, and
stop setting NSW: signed overflow is possible.  Thanks to Dan
for pointing these out.

llvm-svn: 122790
1 file changed
tree: 60fba1cc46aa3476ea1033a3ab6dcfed947e0122
  1. clang/
  2. compiler-rt/
  3. debuginfo-tests/
  4. libcxx/
  5. lldb/
  6. llvm/