Use a SmallVector instead of std::vector for ResOperands.

There's almost always a small number of instruction operands, so
use a SmallVector and save on heap allocations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155143 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed