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/DebugInfo/namespace_function_definition.ll b/llvm/test/DebugInfo/namespace_function_definition.ll
index 6983a687aba..f7a34c1827d 100644
--- a/llvm/test/DebugInfo/namespace_function_definition.ll
+++ b/llvm/test/DebugInfo/namespace_function_definition.ll
@@ -34,7 +34,7 @@ attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointe
 !1 = !DIFile(filename: "namespace_function_definition.cpp", directory: "/tmp/dbginfo")
 !2 = !{}
 !3 = !{!4}
-!4 = !DISubprogram(name: "func", linkageName: "_ZN2ns4funcEv", line: 2, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 2, file: !1, scope: !5, type: !6, function: void ()* @_ZN2ns4funcEv, variables: !2)
+!4 = distinct !DISubprogram(name: "func", linkageName: "_ZN2ns4funcEv", line: 2, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 2, file: !1, scope: !5, type: !6, function: void ()* @_ZN2ns4funcEv, variables: !2)
 !5 = !DINamespace(name: "ns", line: 1, file: !1, scope: null)
 !6 = !DISubroutineType(types: !7)
 !7 = !{null}