[llvm] [SPIR-V] Fix BB ordering & register lifetime (PR #111026)

[Nathan Gauër via llvm-commits]

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@@ -102,6 +104,8 @@ BasicBlock *getDesignatedMergeBlock(Instruction *I) {
 // Returns the continue block designated by I if I is an OpLoopMerge, nullptr
 // otherwise.
 BasicBlock *getDesignatedContinueBlock(Instruction *I) {
+  if (I == nullptr)
+    return nullptr;
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Keenuts wrote:

done

https://github.com/llvm/llvm-project/pull/111026