[llvm] [X86][MC] Report error when the instruction length exceeds 15 bytes (PR #83708)

[Evgenii Kudriashov via llvm-commits]

e-kud wrote:

@KanRobert Thank you for the explanation!

> We usually don't verify the inline asemble in codegen, because we assume user should be responsible for their mistakes in inline asemble.

@phoebewang I agree but we still check the correctness of opcodes and operands. I wondered if we can check the size as well. Apparently it's not so straightforward, especially including your example with compiler generated SIB for the "m" constrain.

https://github.com/llvm/llvm-project/pull/83708