[clang] [RISCV][Sema] Add feature check for target attribute to VSETVL intrinsics (PR #126064)

[Pengcheng Wang via cfe-commits]

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@@ -623,13 +623,37 @@ bool SemaRISCV::CheckBuiltinFunctionCall(const TargetInfo &TI,
   }
   }
 
+  auto checkVsetvl = [&](unsigned SEWOffset,
+                                        unsigned LMULOffset) -> bool {
+    const FunctionDecl *FD = SemaRef.getCurFunctionDecl();
+    llvm::StringMap<bool> FunctionFeatureMap;
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wangpc-pp wrote:

Put it at the entry of `CheckBuiltinFunctionCall` may not be enough, we still need to construct the feature map for each builtin inside a function. This map should be constructed when entering a function scope.

https://github.com/llvm/llvm-project/pull/126064