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/Sparc/gnu-window-save.ll b/llvm/test/DebugInfo/Sparc/gnu-window-save.ll
index f865c95049a..edfc7bb27ef 100644
--- a/llvm/test/DebugInfo/Sparc/gnu-window-save.ll
+++ b/llvm/test/DebugInfo/Sparc/gnu-window-save.ll
@@ -59,7 +59,7 @@ attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "n
 !1 = !DIFile(filename: "hello.c", directory: "/home/venkatra/work/benchmarks/test/hello")
 !2 = !{}
 !3 = !{!4}
-!4 = !DISubprogram(name: "main", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 4, file: !1, scope: !5, type: !6, function: i32 ()* @main, variables: !2)
+!4 = distinct !DISubprogram(name: "main", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 4, file: !1, scope: !5, type: !6, function: i32 ()* @main, variables: !2)
 !5 = !DIFile(filename: "hello.c", directory: "/home/venkatra/work/benchmarks/test/hello")
 !6 = !DISubroutineType(types: !7)
 !7 = !{!8}