[llvm] [RISCV] Don't set AVL if only zeroness is demanded (PR #74049)

[Craig Topper via llvm-commits]

topperc wrote:

I recently pulled this patch in our downstream and I'm seeing an assertion failure

llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp:561: unsigned int (anonymous namespace)::VSETVLIInfo::encodeVTYPE() const: Assertion `isValid() && !isUnknown() && !SEWLMULRatioOnly && "Can't encode VTYPE for uninitialized or unknown"' failed.

https://github.com/llvm/llvm-project/pull/74049