[MLIR][SPIRVToLLVM] Conversion of SPIR-V array, runtime array, and pointer types

This patch adds type conversion for 4 SPIR-V types: array, runtime array, pointer
and struct. This conversion is integrated using a separate function
populateSPIRVToLLVMTypeConversion() that adds new type conversions. At the moment,
this is a basic skeleton that allows to perfom conversion from SPIR-V array,
runtime array and pointer types to LLVM typesystem. There is no support of array
strides or storage classes. These will be supported on the case by case basis.

Reviewed By: antiagainst

Differential Revision: https://reviews.llvm.org/D83399