[llvm] [SPIR-V] Handle ASM with multiple outputs (PR #187128)

[Steven Perron via llvm-commits]

https://github.com/s-perron commented:

Just some questions about some assumptions. You seem to assume there is always a return value from the inline asm, which leads to a non-empty constraint string. Is that always true?

https://github.com/llvm/llvm-project/pull/187128