DI: Disallow uniquable DICompileUnits

Since r241097, `DIBuilder` has only created distinct `DICompileUnit`s.
The backend is liable to start relying on that (if it hasn't already),
so make uniquable `DICompileUnit`s illegal and automatically upgrade old
bitcode.  This is a nice cleanup, since we can remove an unnecessary
`DenseSet` (and the associated uniquing info) from `LLVMContextImpl`.

Almost all the testcases were updated with this script:

    git grep -e '= !DICompileUnit' -l -- test |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's,= !DICompileUnit,= distinct !DICompileUnit,'

I imagine something similar should work for out-of-tree testcases.

llvm-svn: 243885

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/test/DebugInfo/X86/vector.ll b/llvm/test/DebugInfo/X86/vector.ll
index f95ad956dea..3e2092bd806 100644
--- a/llvm/test/DebugInfo/X86/vector.ll
+++ b/llvm/test/DebugInfo/X86/vector.ll
@@ -12,7 +12,7 @@
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!13}
 
-!0 = !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.3 (trunk 171825) (llvm/trunk 171822)", isOptimized: false, emissionKind: 0, file: !12, enums: !1, retainedTypes: !1, subprograms: !1, globals: !3, imports:  !1)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.3 (trunk 171825) (llvm/trunk 171822)", isOptimized: false, emissionKind: 0, file: !12, enums: !1, retainedTypes: !1, subprograms: !1, globals: !3, imports:  !1)
 !1 = !{}
 !3 = !{!5}
 !5 = !DIGlobalVariable(name: "a", line: 3, isLocal: false, isDefinition: true, scope: null, file: !6, type: !7, variable: <4 x i32>* @a)