[CodeGen][GC] Remove `GCInfoPrinter` (#75033)

This pass is broken and looks like no one uses it for the last 15+ years.

```c++
bool Printer::runOnFunction(Function &F) {
  if (F.hasGC())
    return false;

  GCFunctionInfo *FD = &getAnalysis<GCModuleInfo>().getFunctionInfo(F);
```
```c++
GCFunctionInfo &GCModuleInfo::getFunctionInfo(const Function &F) {
  assert(!F.isDeclaration() && "Can only get GCFunctionInfo for a definition!");
  assert(F.hasGC()); // Equivalent to `assert(false);` when called by `Printer::runOnFunction`
```

See also #74972.

1 files changed, 4 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp
index 1f7c949..b82fe5f 100644
--- a/llvm/lib/CodeGen/TargetPassConfig.cpp
+++ b/llvm/lib/CodeGen/TargetPassConfig.cpp
@@ -113,10 +113,9 @@ static cl::opt<bool> DisableMergeICmps("disable-mergeicmps",
     cl::init(false), cl::Hidden);
 static cl::opt<bool> PrintLSR("print-lsr-output", cl::Hidden,
     cl::desc("Print LLVM IR produced by the loop-reduce pass"));
-static cl::opt<bool> PrintISelInput("print-isel-input", cl::Hidden,
-    cl::desc("Print LLVM IR input to isel pass"));
-static cl::opt<bool> PrintGCInfo("print-gc", cl::Hidden,
-    cl::desc("Dump garbage collector data"));
+static cl::opt<bool>
+    PrintISelInput("print-isel-input", cl::Hidden,
+                   cl::desc("Print LLVM IR input to isel pass"));
 static cl::opt<cl::boolOrDefault>
     VerifyMachineCode("verify-machineinstrs", cl::Hidden,
                       cl::desc("Verify generated machine code"));
@@ -491,7 +490,6 @@ CGPassBuilderOption llvm::getCGPassBuilderOption() {
   SET_BOOLEAN_OPTION(DisableSelectOptimize)
   SET_BOOLEAN_OPTION(PrintLSR)
   SET_BOOLEAN_OPTION(PrintISelInput)
-  SET_BOOLEAN_OPTION(PrintGCInfo)
 
   return Opt;
 }
@@ -1211,10 +1209,7 @@ void TargetPassConfig::addMachinePasses() {
   }
 
   // GC
-  if (addGCPasses()) {
-    if (PrintGCInfo)
-      addPass(createGCInfoPrinter(dbgs()));
-  }
+  addGCPasses();
 
   // Basic block placement.
   if (getOptLevel() != CodeGenOptLevel::None)