[clang] [flang] [llvm] Introduce -fexperimental-loop-fuse to clang and flang (PR #142686)

[Ryotaro Kasuga via cfe-commits]

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@@ -204,6 +205,10 @@ static cl::opt<bool>
     EnableLoopInterchange("enable-loopinterchange", cl::init(false), cl::Hidden,
                           cl::desc("Enable the LoopInterchange Pass"));
 
+static cl::opt<bool> EnableLoopFusion("enable-loopfusion", cl::init(false),
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kasuga-fj wrote:

If I understand correctly, the current situation is that "we can pass `-mllvm -enable-loopfusion` to clang, but LoopFuse does not actually run". If so, I think it's confusing.

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