Base.MainInclude regressions in v1.11, eval and include

[nsajko]

Don't known how much of these changes are intentional, but at least some of them are regressions. For example, v1.10 documents Base.MainInclude.include, but in v1.11 and nightly there's no include defined in Base.MainInclude.

Furthermore, Main.eval != Base.MainInclude.eval is weird.

Behavior on v1.10 and earlier:

julia> @which Main.eval
Base.MainInclude

julia> @which Base.MainInclude.eval
Base.MainInclude

julia> @which Main.include
Base.MainInclude

julia> @which Base.MainInclude.include
Base.MainInclude

julia> versioninfo()
Julia Version 1.10.3
Commit 0b4590a5507 (2024-04-30 10:59 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × AMD Ryzen 3 5300U with Radeon Graphics
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-15.0.7 (ORCJIT, znver2)
Threads: 1 default, 0 interactive, 1 GC (on 8 virtual cores)

Behavior on v1.11 and nightly:

julia> @which Main.eval
Main

julia> @which Base.MainInclude.eval
Core

julia> @which Main.include
Main

julia> isdefined(Base.MainInclude, :include)
false

julia> versioninfo()
Julia Version 1.11.0-beta1
Commit 08e1fc0abb9 (2024-04-10 08:40 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × AMD Ryzen 3 5300U with Radeon Graphics
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, znver2)
Threads: 1 default, 0 interactive, 1 GC (on 8 virtual cores)

[fredrikekre]

Duplicate of #54057.