Regression in vcat performance

[kpamnany]

               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.7.1 (2021-12-22)
 _/ |\__'_|_|_|\__'_|  |
|__/                   |

julia> using BenchmarkTools

julia> begin
           a = Any[rand(Int) for _ in 1:10]
           num = 5
           @btime vcat($a, $num);
       end;
  43.047 ns (1 allocation: 144 bytes)

               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.8.0-rc3 (2022-07-13)
 _/ |\__'_|_|_|\__'_|  |
|__/                   |

julia> using BenchmarkTools

julia> begin
           a = Any[rand(Int) for _ in 1:10]
           num = 5
           @btime vcat($a, $num);
       end;
  1.067 μs (14 allocations: 464 bytes)

[gbaraldi]

This is fast again on master for reference.

[kpamnany]

This was fixed in #45028 which will be backported to 1.8.0.