DebugInfo: Avoid some MMI::hasDebugInfo checks

I assume getSubprogram will do the correct thing in hasDebugInfo,
and this is redundant with the debug_compile_units distance check.
This is in preparation for removing the field.

Author: arsenm

llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp

@@ -241,10 +241,7 @@ bool DebugHandlerBase::isUnsignedDIType(const DIType *Ty) {
          Ty->getTag() == dwarf::DW_TAG_unspecified_type;
 }
 
-static bool hasDebugInfo(const MachineModuleInfo *MMI,
-                         const MachineFunction *MF) {
-  if (!MMI->hasDebugInfo())
-    return false;
+static bool hasDebugInfo(const MachineFunction *MF) {
   auto *SP = MF->getFunction().getSubprogram();
   if (!SP)
     return false;
@@ -258,7 +255,7 @@ static bool hasDebugInfo(const MachineModuleInfo *MMI,
 void DebugHandlerBase::beginFunction(const MachineFunction *MF) {
   PrevInstBB = nullptr;
 
-  if (!Asm || !hasDebugInfo(MMI, MF)) {
+  if (!Asm || !hasDebugInfo(MF)) {
     skippedNonDebugFunction();
     return;
   }
@@ -415,7 +412,7 @@ void DebugHandlerBase::endInstruction() {
 }
 
 void DebugHandlerBase::endFunction(const MachineFunction *MF) {
-  if (Asm && hasDebugInfo(MMI, MF))
+  if (Asm && hasDebugInfo(MF))
     endFunctionImpl(MF);
   DbgValues.clear();
   DbgLabels.clear();

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -1148,14 +1148,15 @@ sortGlobalExprs(SmallVectorImpl<DwarfCompileUnit::GlobalExpr> &GVEs) {
 void DwarfDebug::beginModule(Module *M) {
   DebugHandlerBase::beginModule(M);
 
-  if (!Asm || !MMI->hasDebugInfo())
+  if (!Asm)
     return;
 
   unsigned NumDebugCUs = std::distance(M->debug_compile_units_begin(),
                                        M->debug_compile_units_end());
+  if (NumDebugCUs == 0)
+    return;
+
   assert(NumDebugCUs > 0 && "Asm unexpectedly initialized");
-  assert(MMI->hasDebugInfo() &&
-         "DebugInfoAvailabilty unexpectedly not initialized");
   SingleCU = NumDebugCUs == 1;
   DenseMap<DIGlobalVariable *, SmallVector<DwarfCompileUnit::GlobalExpr, 1>>
       GVMap;