[llvm] [RISCV] Assert extensions are sorted at compile time. NFCI (PR #77442)

[Craig Topper via llvm-commits]

topperc wrote:

Does this give a good error message when it fails? I've inserted a print in the runtime code more than once due to bad merge resolution in my downstream to figure out which extension is misplaced.

https://github.com/llvm/llvm-project/pull/77442