[MachineVerifier] Try harder to verify LiveStacks

Verify the LiveStacks analysis after a pass that claims to preserve it,
even if there are no further passes (apart from the verifier itself)
that would use the analysis.

Differential Revision: https://reviews.llvm.org/D129200

diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index db04f2b..7a008ba 100644 (file)
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -293,6 +293,7 @@ namespace {
       }
 
     void getAnalysisUsage(AnalysisUsage &AU) const override {
+      AU.addUsedIfAvailable<LiveStacks>();
       AU.setPreservesAll();
       MachineFunctionPass::getAnalysisUsage(AU);
     }