[clang] [llvm] [RISCV] Support `svukte` extension (PR #115657)

[Craig Topper via cfe-commits]

================
@@ -158,6 +158,7 @@ on support follow.
      ``Svinval``       Assembly Support
      ``Svnapot``       Assembly Support
      ``Svpbmt``        Supported
+     ``Svukte``        Supported
----------------
topperc wrote:

It has to be experimental until ratified. The ratification process can still change a frozen spec.

https://github.com/llvm/llvm-project/pull/115657