[clang] [llvm] [RISCV] Add Zilsd and Zclsd Extensions (PR #131094)

[via llvm-commits]

================
@@ -176,6 +176,13 @@ def HasStdExtZicfiss : Predicate<"Subtarget->hasStdExtZicfiss()">,
                                           "'Zicfiss' (Shadow stack)">;
 def NoHasStdExtZicfiss : Predicate<"!Subtarget->hasStdExtZicfiss()">;
 
+def FeatureStdExtZilsd
+    : RISCVExtension<1, 0,
+                     "Load/Store Pair Instructions">;
----------------
dong-miao wrote:

You mean what benefits does the zilsd extension bring to RV32?  The relevant benefits are mentioned in Chapter 1. Introduction of the [specification document](https://drive.google.com/file/d/1oMMxKJSuNKNcjiZdJEPeUqOCxr8VcxCn/view).

https://github.com/llvm/llvm-project/pull/131094