DI: Require subprogram definitions to be distinct

As a follow-up to r246098, require `DISubprogram` definitions
(`isDefinition: true`) to be 'distinct'.  Specifically, add an assembler
check, a verifier check, and bitcode upgrading logic to combat testcase
bitrot after the `DIBuilder` change.

While working on the testcases, I realized that
test/Linker/subprogram-linkonce-weak-odr.ll isn't relevant anymore.  Its
purpose was to check for a corner case in PR22792 where two subprogram
definitions match exactly and share the same metadata node.  The new
verifier check, requiring that subprogram definitions are 'distinct',
precludes that possibility.

I updated almost all the IR with the following script:

    git grep -l -E -e '= !DISubprogram\(.* isDefinition: true' |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's/= \(!DISubprogram(.*, isDefinition: true\)/= distinct \1/'

Likely some variant of would work for out-of-tree testcases.

llvm-svn: 246327

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/test/Linker/2011-08-04-DebugLoc2.ll b/llvm/test/Linker/2011-08-04-DebugLoc2.ll
index 073a6359d8d..8b23cbb7d65 100644
--- a/llvm/test/Linker/2011-08-04-DebugLoc2.ll
+++ b/llvm/test/Linker/2011-08-04-DebugLoc2.ll
@@ -15,7 +15,7 @@ define i32 @bar() nounwind ssp {
 !llvm.dbg.sp = !{!1}
 
 !0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "Apple clang version 3.0 (tags/Apple/clang-209.11) (based on LLVM 3.0svn)", isOptimized: true, emissionKind: 0, file: !8, enums: !9, retainedTypes: !9, subprograms: !10)
-!1 = !DISubprogram(name: "bar", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, file: !8, scope: !2, type: !3, function: i32 ()* @bar)
+!1 = distinct !DISubprogram(name: "bar", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, file: !8, scope: !2, type: !3, function: i32 ()* @bar)
 !2 = !DIFile(filename: "b.c", directory: "/private/tmp")
 !3 = !DISubroutineType(types: !4)
 !4 = !{!5}