[clang] [clang][CodeGen] Fix metadata when vectorization is disabled by pragma (PR #135163)

[Ryotaro Kasuga via cfe-commits]

kasuga-fj wrote:

I somehow missed this until now, but it turns out that specifying `vectorize(disable) vectorize_width(scalable)` causes an error due to "incompatible directives" (godbolt: https://godbolt.org/z/vv1vKqdTn). I had been concerned that the ambiguity here might make implementation difficult, but it seems that fear was unfounded. I think it can probably be achieved with the current mechanism. My bad, sorry...

https://github.com/llvm/llvm-project/pull/135163