[clang] [llvm] [RISCV] Add Smrnmi extension (PR #111668)

[Craig Topper via cfe-commits]

================
@@ -276,6 +276,14 @@ foreach i = 0...15 in {
 foreach i = 0...63 in
   def : SysReg<"pmpaddr"#i, !add(0x3B0, i)>;
 
+//===----------------------------------------------------------------------===//
+// Machine Non-Maskable Interrupt Handling
+//===----------------------------------------------------------------------===//
+def:SysReg<"mnscratch",0x740>;
----------------
topperc wrote:

ARen't these already in the file?

```
//===-----------------------------------------------                             
// Resumable Non-Maskable Interrupts(Smrnmi) CSRs                                
//===-----------------------------------------------                             
def : SysReg<"mnscratch", 0x740>;                                                
def : SysReg<"mnepc", 0x741>;                                                    
def : SysReg<"mncause", 0x742>;                                                  
def : SysReg<"mnstatus", 0x744>;
```

https://github.com/llvm/llvm-project/pull/111668