llvm: Use correct type for splat mask

[maurer]

After llvm/llvm-project#195486 , LLVM has explicit handling for null pointers in simd operations instead of using special handling based on zeroes.

This causes LLVM with asserts enabled to detect an improperly typed mask passed to splat (if the output vector does not have i32 elements), and can cause SIGSEGV in more complex cases with asserts disabled.

@rustbot label: +llvm-main

r? @durin42

[rustbot]

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  • 3c83d3a

[nikic]

@bors r+ rollup

So previously this ended up creating a shuffle mask like <ptr null, ptr null, ...> and we got away with this because LLVM internally doesn't actually store shuffle masks as constants and the code happened to not care that this the all-zero value had the wrong type.

[rust-bors]

📌 Commit 3c83d3a has been approved by nikic

It is now in the queue for this repository.