[MathExtras] Remove unnecessary cast of a constant 1 in a subtract.

Pretty sure this will automatically promoted to match the type of the other operand of the subtract. There's plenty of other similar code around here without this cast.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309653 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed