Refactor filename/directory in DICompileUnit into a DIFile

This is the next step towards making the metadata for DIScopes have a common
prefix rather than having to delegate based on their tag type.

llvm-svn: 176913
diff --git a/llvm/test/DebugInfo/X86/2011-09-26-GlobalVarContext.ll b/llvm/test/DebugInfo/X86/2011-09-26-GlobalVarContext.ll
index 386ff2c..8d14a50 100644
--- a/llvm/test/DebugInfo/X86/2011-09-26-GlobalVarContext.ll
+++ b/llvm/test/DebugInfo/X86/2011-09-26-GlobalVarContext.ll
@@ -18,7 +18,7 @@
 
 !llvm.dbg.cu = !{!0}
 
-!0 = metadata !{i32 786449, i32 0, i32 12, metadata !"test.c", metadata !"/work/llvm/vanilla/test/DebugInfo", metadata !"clang version 3.0 (trunk)", i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !12, metadata !""} ; [ DW_TAG_compile_unit ]
+!0 = metadata !{i32 786449, i32 0, i32 12, metadata !6, metadata !"clang version 3.0 (trunk)", i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !12, metadata !""} ; [ DW_TAG_compile_unit ]
 !1 = metadata !{i32 0}
 !3 = metadata !{metadata !5}
 !5 = metadata !{i32 720942, i32 0, metadata !6, metadata !"f", metadata !"f", metadata !"", metadata !6, i32 3, metadata !7, i1 false, i1 true, i32 0, i32 0, i32 0, i32 0, i1 false, i32 ()* @f, null, null, metadata !10} ; [ DW_TAG_subprogram ]