[clang] [flang] [llvm] add -floop-fuse to clang and flang (PR #142686)

[Tarun Prabhu via llvm-commits]

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@@ -1332,6 +1333,7 @@ runThinLTOBackend(CompilerInstance &CI, ModuleSummaryIndex *CombinedIndex,
   Conf.SampleProfile = std::move(SampleProfile);
   Conf.PTO.LoopUnrolling = CGOpts.UnrollLoops;
   Conf.PTO.LoopInterchange = CGOpts.InterchangeLoops;
+  Conf.PTO.LoopFuse = CGOpts.FuseLoops;
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tarunprabhu wrote:

NIT
```suggestion
  Conf.PTO.LoopFusion = CGOpts.FuseLoops;
```

https://github.com/llvm/llvm-project/pull/142686