[clang] [llvm] [Clang][Driver] Add an option to control loop-interchange (PR #125830)

[Michael Kruse via cfe-commits]

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@@ -316,6 +312,7 @@ PipelineTuningOptions::PipelineTuningOptions() {
   LoopVectorization = true;
   SLPVectorization = false;
   LoopUnrolling = true;
+  LoopInterchange = false;
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Meinersbur wrote:

The default of `LoopInterchange` could be initialized with `EnableLoopInterchange`, as done by `MergeFunctions = EnableMergeFunction`.

Not important for me, but someone might want to keep `-mllvm -enable-loopinterchange` working, e.g. for non-Clang drivers.

https://github.com/llvm/llvm-project/pull/125830