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

docs/SourceLevelDebugging.html

@@ -452,6 +452,7 @@ global variables are collected inside the named metadata
   metadata, ;; Reference to type descriptor
   i1,       ;; True if the global is local to compile unit (static)
   i1,       ;; True if the global is defined in the compile unit (not extern)
+  i32,      ;; Line number where the scope of the subprogram begins
   i32,      ;; Virtuality, e.g. dwarf::DW_VIRTUALITY__virtual
   i32,      ;; Index into a virtual function
   metadata, ;; indicates which base type contains the vtable pointer for the