Add a line number for the scope of the function (starting at the first
brace) so that we get more accurate line number information about the
declaration of a given function and the line where the function
first starts.

Part of rdar://11026482

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153916 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 2490172..420f2cd 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1193,12 +1193,19 @@
 }
 
 /// getFnDebugLoc - Walk up the scope chain of given debug loc and find
-/// line number  info for the function.
+/// line number info for the function.
 static DebugLoc getFnDebugLoc(DebugLoc DL, const LLVMContext &Ctx) {
   const MDNode *Scope = getScopeNode(DL, Ctx);
   DISubprogram SP = getDISubprogram(Scope);
-  if (SP.Verify()) 
-    return DebugLoc::get(SP.getLineNumber(), 0, SP);
+  if (SP.Verify()) {
+    // Check for number of operands since the compatibility is
+    // cheap here.
+    if (Scope->getNumOperands() > 19)
+      return DebugLoc::get(SP.getScopeLineNumber(), 0, SP);
+    else
+      return DebugLoc::get(SP.getLineNumber(), 0, SP);
+  }
+
   return DebugLoc();
 }