Add a field to the compile unit of where we plan on splitting out

the debug info for -gsplit-dwarf so we can encode that location
in the skeleton cu.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175933 91177308-0d34-0410-b5e6-96231b3b80d8

lib/IR/DIBuilder.cpp

@@ -76,7 +76,7 @@ static MDNode *getNonCompileUnitScope(MDNode *N) {
 void DIBuilder::createCompileUnit(unsigned Lang, StringRef Filename,
                                   StringRef Directory, StringRef Producer,
                                   bool isOptimized, StringRef Flags,
-                                  unsigned RunTimeVer) {
+                                  unsigned RunTimeVer, StringRef SplitName) {
   assert(((Lang <= dwarf::DW_LANG_Python && Lang >= dwarf::DW_LANG_C89) ||
           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
          "Invalid Language tag");
@@ -106,7 +106,8 @@ void DIBuilder::createCompileUnit(unsigned Lang, StringRef Filename,
     TempEnumTypes,
     TempRetainTypes,
     TempSubprograms,
-    TempGVs
+    TempGVs,
+    MDString::get(VMContext, SplitName)
   };
   TheCU = DICompileUnit(MDNode::get(VMContext, Elts));