[llvm] [clang] [SPARC] Consume `tune-cpu` directive in the backend (PR #77195)

[Sergei Barannikov via cfe-commits]

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@@ -45,7 +45,8 @@ class SparcSubtarget : public SparcGenSubtargetInfo {
 
 public:
   SparcSubtarget(const Triple &TT, const std::string &CPU,
-                 const std::string &FS, const TargetMachine &TM, bool is64bit);
+                 const std::string &TuneCPU, const std::string &FS,
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s-barannikov wrote:

While here, could change all `const std::string &` to `StringRef` and/or remove the `TT` parameter (it can be obtained as `TM.getTargetTriple()`.).


https://github.com/llvm/llvm-project/pull/77195