[DAGCombine] Remove LoadedSlice::Cost default 'ForCodeSize' constructor arguments. NFCI.
[DAGCombine] Remove LoadedSlice::Cost default 'ForCodeSize' constructor arguments. NFCI.

These were always being passed in and it allowed me to add the explicit tag to stop a cppcheck warning about 1 argument constructors.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@370189 91177308-0d34-0410-b5e6-96231b3b80d8

GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm