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

[Madhur Amilkanthwar via llvm-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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madhur13490 wrote:

Hmm.. yeah. I added the OR condition to add the pass in pipeline. This seems to be missing for loop interchange too but I can take that in the next patch. 
I would like to add a test for this, but I'm not sure where the right place is. Maybe `clang_f_opts.c`?

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