[clang] [flang] [mlir] [flang] Add basic -mtune support (PR #95043)

[Christian Ulmann via cfe-commits]

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@@ -411,6 +412,13 @@ void Flang::addTargetOptions(const ArgList &Args,
   }
 
   // TODO: Add target specific flags, ABI, mtune option etc.
+  if (const Arg *A = Args.getLastArg(options::OPT_mtune_EQ)) {
+    CmdArgs.push_back("-tune-cpu");
+    if (strcmp(A->getValue(), "native") == 0)
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Dinistro wrote:

Nit: `strcmp` is a C function. I assume that `A->getValue()` returns a StringRef, or something else that supports normal `==` comparison. 

https://github.com/llvm/llvm-project/pull/95043