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/Transforms/ObjCARC/ensure-that-exception-unwind-path-is-visited.ll b/llvm/test/Transforms/ObjCARC/ensure-that-exception-unwind-path-is-visited.ll
index 67a8049d681..07f915201b2 100644
--- a/llvm/test/Transforms/ObjCARC/ensure-that-exception-unwind-path-is-visited.ll
+++ b/llvm/test/Transforms/ObjCARC/ensure-that-exception-unwind-path-is-visited.ll
@@ -113,7 +113,7 @@ declare void @llvm.dbg.value(metadata, i64, metadata, metadata) nounwind readnon
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!33, !34, !35, !36, !61}
 
-!0 = !DICompileUnit(language: DW_LANG_ObjC, producer: "clang version 3.3 ", isOptimized: true, runtimeVersion: 2, emissionKind: 0, file: !60, enums: !1, retainedTypes: !1, subprograms: !3, globals: !1)
+!0 = distinct !DICompileUnit(language: DW_LANG_ObjC, producer: "clang version 3.3 ", isOptimized: true, runtimeVersion: 2, emissionKind: 0, file: !60, enums: !1, retainedTypes: !1, subprograms: !3, globals: !1)
 !1 = !{}
 !3 = !{!5, !27}
 !5 = !DISubprogram(name: "main", line: 9, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: true, scopeLine: 10, file: !60, scope: !6, type: !7, function: i32 ()* @main, variables: !11)