[llvm] [SPIRV] Fix constant materialization for width > 64bit (PR #180182)

[Dmitry Sidorov via llvm-commits]

MrSidims wrote:

Created https://github.com/llvm/llvm-project/pull/180218 to address wrong number of words used for constants with 64<width<128

https://github.com/llvm/llvm-project/pull/180182