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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246327 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 1 deletions

diff --git a/test/CodeGen/Hexagon/hwloop-dbg.ll b/test/CodeGen/Hexagon/hwloop-dbg.ll
index 91d54947bed..af208b3a4da 100644
--- a/test/CodeGen/Hexagon/hwloop-dbg.ll
+++ b/test/CodeGen/Hexagon/hwloop-dbg.ll
@@ -40,7 +40,7 @@ declare void @llvm.dbg.value(metadata, i64, metadata, metadata) nounwind readnon
 !0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "QuIC LLVM Hexagon Clang version 6.1-pre-unknown, (git://git-hexagon-aus.quicinc.com/llvm/clang-mainline.git e9382867661454cdf44addb39430741578e9765c) (llvm/llvm-mainline.git 36412bb1fcf03ed426d4437b41198bae066675ac)", isOptimized: true, emissionKind: 1, file: !28, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2)
 !2 = !{}
 !3 = !{!5}
-!5 = !DISubprogram(name: "foo", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 1, file: !28, scope: null, type: !7, function: void (i32*, i32*)* @foo, variables: !11)
+!5 = distinct !DISubprogram(name: "foo", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 1, file: !28, scope: null, type: !7, function: void (i32*, i32*)* @foo, variables: !11)
 !6 = !DIFile(filename: "hwloop-dbg.c", directory: "/usr2/kparzysz/s.hex/t")
 !7 = !DISubroutineType(types: !8)
 !8 = !{null, !9, !9}