[MLIR][SROA][Mem2Reg] Add data layout to interface methods

This commit expends the Mem2Reg and SROA interface methods with passed
in handles to a `DataLayout` structure. This is done to avoid
superfluous retreiving of data layouts during each conversion of
intrinsics.

This change, additionally, enables subsequent changes to make the LLVM
dialect implementation of these interfaces type agnostic.