IR: Add 'distinct' MDNodes to bitcode and assembly

Propagate whether `MDNode`s are 'distinct' through the other types of IR
(assembly and bitcode).  This adds the `distinct` keyword to assembly.

Currently, no one actually calls `MDNode::getDistinct()`, so these nodes
only get created for:

  - self-references, which are never uniqued, and
  - nodes whose operands are replaced that hit a uniquing collision.

The concept of distinct nodes is still not quite first-class, since
distinct-ness doesn't yet survive across `MapMetadata()`.

Part of PR22111.

llvm-svn: 225474

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/X86/already-vectorized.ll b/llvm/test/Transforms/LoopVectorize/X86/already-vectorized.ll
index f3191c86f4a..29d74a0645e 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/already-vectorized.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/already-vectorized.ll
@@ -39,8 +39,8 @@ for.end:                                          ; preds = %for.body
 }
 
 ; Now, we check for the Hint metadata
-; CHECK: [[vect]] = !{[[vect]], [[width:![0-9]+]], [[unroll:![0-9]+]]}
+; CHECK: [[vect]] = distinct !{[[vect]], [[width:![0-9]+]], [[unroll:![0-9]+]]}
 ; CHECK: [[width]] = !{!"llvm.loop.vectorize.width", i32 1}
 ; CHECK: [[unroll]] = !{!"llvm.loop.interleave.count", i32 1}
-; CHECK: [[scalar]] = !{[[scalar]], [[width]], [[unroll]]}
+; CHECK: [[scalar]] = distinct !{[[scalar]], [[width]], [[unroll]]}