[llvm] [LoopVectorize] Enable more early exit vectorisation tests (PR #117008)

[Paul Walker via llvm-commits]

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@@ -10177,13 +10202,33 @@ bool LoopVectorizePass::processLoop(Loop *L) {
     return false;
   }
 
-  if (LVL.hasUncountableEarlyExit() && !EnableEarlyExitVectorization) {
-    reportVectorizationFailure("Auto-vectorization of loops with uncountable "
-                               "early exit is not enabled",
-                               "Auto-vectorization of loops with uncountable "
-                               "early exit is not enabled",
-                               "UncountableEarlyExitLoopsDisabled", ORE, L);
-    return false;
+  if (LVL.hasUncountableEarlyExit()) {
+    if (!EnableEarlyExitVectorization) {
+      reportVectorizationFailure("Auto-vectorization of loops with uncountable "
+                                 "early exit is not enabled",
+                                 "Auto-vectorization of loops with uncountable "
+                                 "early exit is not enabled",
+                                 "UncountableEarlyExitLoopsDisabled", ORE, L);
+      return false;
+    }
+
+    // Needed to prevent InnerLoopVectorizer::fixupIVUsers from crashing.
----------------
paulwalker-arm wrote:

Can you elaborate on this comment. What scenario causes `fixupIVUsers` to crash? I'm not after huge detail but if there is a specific property of a user that is not supported then it would be nice to mention it here.

https://github.com/llvm/llvm-project/pull/117008