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/CodeGen/PowerPC/dbg.ll b/llvm/test/CodeGen/PowerPC/dbg.ll
index f29bc0eaae4..9b33134babe 100644
--- a/llvm/test/CodeGen/PowerPC/dbg.ll
+++ b/llvm/test/CodeGen/PowerPC/dbg.ll
@@ -20,7 +20,7 @@ declare void @llvm.dbg.value(metadata, i64, metadata, metadata) nounwind readnon
 !0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.1", isOptimized: true, emissionKind: 0, file: !21, enums: !1, retainedTypes: !1, subprograms: !3, globals: !1, imports: !1)
 !1 = !{}
 !3 = !{!5}
-!5 = !DISubprogram(name: "main", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, file: !21, scope: null, type: !7, function: i32 (i32, i8**)* @main, variables: !13)
+!5 = distinct !DISubprogram(name: "main", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, file: !21, scope: null, type: !7, function: i32 (i32, i8**)* @main, variables: !13)
 !6 = !DIFile(filename: "dbg.c", directory: "/src")
 !7 = !DISubroutineType(types: !8)
 !8 = !{!9, !9, !10}