TableGen: Avoid undefined behaviour by doing this shift in int64

Found by ubsan. This was taking a bool and left shifting by 32 - the
result is 64 bit, so we should really do the math in a type it fits
in.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237345 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed