DebugInfo: Fix bad debug info for compile units and types

Fix debug info in these tests, which started failing with a WIP patch to
verify compile units and types.  The problems look like they were all
caused by bitrot.  They fell into these categories:

  - Using `!{i32 0}` instead of `!{}`.
  - Using `!{null}` instead of `!{}`.
  - Using `!MDExpression()` instead of `!{}`.
  - Using `!8` instead of `!{!8}`.
  - `file:` references that pointed at `MDCompileUnit`s instead of the
    same `MDFile` as the compile unit.
  - `file:` references that were numerically off-by-one or (off-by-ten).

llvm-svn: 233415
diff --git a/llvm/test/Transforms/LoopVectorize/dbg.value.ll b/llvm/test/Transforms/LoopVectorize/dbg.value.ll
index f942ecc..c794ca0 100644
--- a/llvm/test/Transforms/LoopVectorize/dbg.value.ll
+++ b/llvm/test/Transforms/LoopVectorize/dbg.value.ll
@@ -45,7 +45,7 @@
 !llvm.module.flags = !{!26}
 
 !0 = !MDCompileUnit(language: DW_LANG_C_plus_plus, producer: "clang", isOptimized: true, emissionKind: 0, file: !25, enums: !1, retainedTypes: !1, subprograms: !2, globals: !11)
-!1 = !{i32 0}
+!1 = !{}
 !2 = !{!3}
 !3 = !MDSubprogram(name: "test", linkageName: "test", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 5, file: !25, scope: !4, type: !5, function: i32 ()* @test, variables: !8)
 !4 = !MDFile(filename: "test", directory: "/path/to/somewhere")