[llvm] [GlobalISel][AArch64] AArch64O0PreLegalizerCombiner: Disable fixed-point iteration (PR #94291)

[Matt Arsenault via llvm-commits]

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@@ -27,6 +28,12 @@
 
 using namespace llvm;
 
+STATISTIC(NumOneIteration, "Number of functions with one iteration");
+STATISTIC(NumTwoIterations, "Number of functions with two iterations");
+STATISTIC(NumThreeIterations, "Number of functions with three iterations");
+STATISTIC(NumFourOrMoreIterations,
+          "Number of functions with four or more iterations");
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arsenm wrote:

Not sure all this variety is needed? We can probably prune this from instcombine now 

https://github.com/llvm/llvm-project/pull/94291