Reapply 79977.
Use MDNodes to encode debug info in llvm IR.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80406 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index 25dfa6e..14ba360 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -333,7 +333,7 @@
 /// getOrCreateDebugLocID - Look up the DebugLocTuple index with the given
 /// source file, line, and column. If none currently exists, create a new
 /// DebugLocTuple, and insert it into the DebugIdMap.
-unsigned MachineFunction::getOrCreateDebugLocID(GlobalVariable *CompileUnit,
+unsigned MachineFunction::getOrCreateDebugLocID(MDNode *CompileUnit,
                                                 unsigned Line, unsigned Col) {
   DebugLocTuple Tuple(CompileUnit, Line, Col);
   DenseMap<DebugLocTuple, unsigned>::iterator II