[llvm] [NVPTX] Emit sub-byte kernel parameters as u8 in AsmPrinter (PR #226091)

[Samarth Narang via llvm-commits]

snarang181 wrote:

The < 8  check covers the sub-byte case, but every non-power-of-two width up to 64 hits the same ptxas error (.u9, .u12, .u24, .u48 → Parsing error near '.uN'), and globals print through the same function (.global .align 1 .u4 g4;). ISel already loads these params with max(8, PowerOf2Ceil(N)) bits, so rounding once in getPTXFundamentalTypeStr fixes all three call sites. Please check #https://github.com/llvm/llvm-project/pull/226113. 

https://github.com/llvm/llvm-project/pull/226091