In certain places in llvm/lib/CodeGen we were relying upon the TypeSize
comparison operators when in fact the code was only ever expecting
either scalar values or fixed width vectors. This patch changes a few
functions that were always expecting to work on scalar or fixed width
types:
- DAGCombiner::mergeTruncStores - deals with scalar integers only.
- DAGCombiner::ReduceLoadWidth - not valid for vectors.
- DAGCombiner::createBuildVecShuffle - should only be used for fixed width vectors.
- SelectionDAGLegalize::ExpandFCOPYSIGN and SelectionDAGLegalize::getSignAsIntValue - only work on scalars.