[llvm] llvm-reduce: Don't print verifier failed machine functions (PR #109673)

[Matt Arsenault via llvm-commits]

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@@ -94,21 +94,24 @@ using namespace llvm;
 namespace {
 
   struct MachineVerifier {
-    MachineVerifier(MachineFunctionAnalysisManager &MFAM, const char *b)
-        : MFAM(&MFAM), Banner(b) {}
+    MachineVerifier(MachineFunctionAnalysisManager &MFAM, const char *b,
+                    raw_ostream *OS)
+        : MFAM(&MFAM), OS(OS ? OS : &nulls()), Banner(b) {}
 
-    MachineVerifier(Pass *pass, const char *b) : PASS(pass), Banner(b) {}
+    MachineVerifier(Pass *pass, const char *b, raw_ostream *OS)
+        : PASS(pass), OS(OS ? OS : &nulls()), Banner(b) {}
 
     MachineVerifier(const char *b, LiveVariables *LiveVars,
                     LiveIntervals *LiveInts, LiveStacks *LiveStks,
-                    SlotIndexes *Indexes)
-        : Banner(b), LiveVars(LiveVars), LiveInts(LiveInts), LiveStks(LiveStks),
-          Indexes(Indexes) {}
+                    SlotIndexes *Indexes, raw_ostream *OS)
+        : OS(OS ? OS : &nulls()), Banner(b), LiveVars(LiveVars),
+          LiveInts(LiveInts), LiveStks(LiveStks), Indexes(Indexes) {}
 
     unsigned verify(const MachineFunction &MF);
 
     MachineFunctionAnalysisManager *MFAM = nullptr;
     Pass *const PASS = nullptr;
+    raw_ostream *OS = nullptr;
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arsenm wrote:

Yes. Originally I was going to add the null checks like the IR verifier does, but it got messy 

https://github.com/llvm/llvm-project/pull/109673