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/X86/MachineSink-DbgValue.ll b/llvm/test/CodeGen/X86/MachineSink-DbgValue.ll
index df693e617c1..2f1a7b082b8 100644
--- a/llvm/test/CodeGen/X86/MachineSink-DbgValue.ll
+++ b/llvm/test/CodeGen/X86/MachineSink-DbgValue.ll
@@ -29,7 +29,7 @@ declare void @llvm.dbg.value(metadata, i64, metadata, metadata) nounwind readnon
 !llvm.module.flags = !{!22}
 
 !0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "Apple clang version 3.0 (tags/Apple/clang-211.10.1) (based on LLVM 3.0svn)", isOptimized: true, emissionKind: 1, file: !20, enums: !21, retainedTypes: !21, subprograms: !18, imports:  null)
-!1 = !DISubprogram(name: "foo", line: 2, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, file: !20, scope: !2, type: !3, function: i32 (i32, i32*)* @foo, variables: !19)
+!1 = distinct !DISubprogram(name: "foo", line: 2, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, file: !20, scope: !2, type: !3, function: i32 (i32, i32*)* @foo, variables: !19)
 !2 = !DIFile(filename: "a.c", directory: "/private/tmp")
 !3 = !DISubroutineType(types: !4)
 !4 = !{!5}