LLVM doesn't deduplicate bbs?

llvm_dup_blocks.ll

bb45:                                             ; preds = %bb37
  %_7.i.i.i.i288 = icmp eq i64 %value.1, 6
  br i1 %_7.i.i.i.i288, label %bb55, label %bb53

bb53:                                             ; preds = %bb45
  %.idx.val.i.i.i42.i = load i8, i8* %13, align 1, !alias.scope !80, !noalias !89
  switch i64 %value.1, label %bb78 [
    i64 7, label %bb63
    i64 8, label %bb72
    i64 9, label %bb80
  ]

bb55:                                             ; preds = %bb45
  %17 = getelementptr inbounds %"core::result::Result<protocol::xkb::LatchLockStateRequest, errors::ParseError>", %"core::result::Result<protocol::xkb::LatchLockStateRequest, errors::Parse\
Error>"* %0, i64 0, i32 2, i64 0
  store i8 0, i8* %17, align 1, !alias.scope !91
  br label %bb3

bb63:                                             ; preds = %bb53
  %18 = getelementptr inbounds %"core::result::Result<protocol::xkb::LatchLockStateRequest, errors::ParseError>", %"core::result::Result<protocol::xkb::LatchLockStateRequest, errors::Parse\
Error>"* %0, i64 0, i32 2, i64 0
  store i8 0, i8* %18, align 1, !alias.scope !94
  br label %bb3

bb72:                                             ; preds = %bb53
  %19 = getelementptr inbounds %"core::result::Result<protocol::xkb::LatchLockStateRequest, errors::ParseError>", %"core::result::Result<protocol::xkb::LatchLockStateRequest, errors::Parse\
Error>"* %0, i64 0, i32 2, i64 0
  store i8 0, i8* %19, align 1, !alias.scope !97
  br label %bb3


bb80:                                             ; preds = %bb53
  %21 = getelementptr inbounds %"core::result::Result<protocol::xkb::LatchLockStateRequest, errors::ParseError>", %"core::result::Result<protocol::xkb::LatchLockStateRequest, errors::Parse\
Error>"* %0, i64 0, i32 2, i64 0
  store i8 0, i8* %21, align 1, !alias.scope !100
  br label %bb3