Remove the (apparently) unnecessary debug info metadata indirection.

The main lists of debug info metadata attached to the compile_unit had an extra
layer of metadata nodes they went through for no apparent reason. This patch
removes that (& still passes just as much of the GDB 7.5 test suite). If anyone
can show evidence as to why these extra metadata nodes are there I'm open to
reverting this patch & documenting why they're there.

llvm-svn: 174266
diff --git a/llvm/test/DebugInfo/line-info.ll b/llvm/test/DebugInfo/line-info.ll
index 2d06297..419098d 100644
--- a/llvm/test/DebugInfo/line-info.ll
+++ b/llvm/test/DebugInfo/line-info.ll
@@ -34,10 +34,8 @@
 !llvm.dbg.cu = !{!0}
 
 !0 = metadata !{i32 786449, i32 0, i32 12, metadata !"list0.c", metadata !"/usr/local/google/home/blaikie/dev/scratch/pr14566", metadata !"clang version 3.3 ", i1 true, i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1} ; [ DW_TAG_compile_unit ] [/usr/local/google/home/blaikie/dev/scratch/pr14566/list0.c] [DW_LANG_C99]
-!1 = metadata !{metadata !2}
-!2 = metadata !{i32 0}
-!3 = metadata !{metadata !4}
-!4 = metadata !{metadata !5, metadata !10}
+!1 = metadata !{i32 0}
+!3 = metadata !{metadata !5, metadata !10}
 !5 = metadata !{i32 786478, i32 0, metadata !6, metadata !"foo", metadata !"foo", metadata !"", metadata !6, i32 1, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32)* @foo, null, null, metadata !1, i32 1} ; [ DW_TAG_subprogram ] [line 1] [def] [foo]
 !6 = metadata !{i32 786473, metadata !"./list0.h", metadata !"/usr/local/google/home/blaikie/dev/scratch/pr14566", null} ; [ DW_TAG_file_type ]
 !7 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, i32 0} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]