[llvm] [clang] [Clang][RISCV] Move getVScaleRange logic into libLLVMFrontendDriver. NFC (PR #77327)

[Luke Lau via llvm-commits]

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@@ -2,6 +2,7 @@ set(LLVM_LINK_COMPONENTS
   Support
   TargetParser
   FrontendOpenMP
+  FrontendDriver
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lukel97 wrote:

I agree. I think I'm coming around to the opinion that this is a bit overkill just to avoid duplicating 16 lines of code.

I'm also thinking that flang and clang don't need to behave exactly the same in this regard. So we don't necessarily need to keep the two in sync. Thoughts? cc @tschuett 

https://github.com/llvm/llvm-project/pull/77327