Revert "use a fixed world for code loading (#49525)"

This reverts commit 59bf9e8.

base/Base.jl

@@ -382,7 +382,6 @@ function __init__()
         # triggering a profile via signals is not implemented on windows
         start_profile_listener()
     end
-    _require_world_age[] = get_world_counter()
     # Prevent spawned Julia process from getting stuck waiting on Tracy to connect.
     delete!(ENV, "JULIA_WAIT_FOR_TRACY")
     if get_bool_env("JULIA_USE_FLISP_PARSER", false) === false

base/loading.jl

@@ -2323,8 +2323,6 @@ end
 # XXX: (this is deprecated, but still used by Distributed)
 const toplevel_load = Ref(true)
 
-const _require_world_age = Ref{UInt}(typemax(UInt))
-
 """
     require(into::Module, module::Symbol)
 
@@ -2347,14 +2345,6 @@ For more details regarding code loading, see the manual sections on [modules](@r
 [parallel computing](@ref code-availability).
 """
 function require(into::Module, mod::Symbol)
-    world = _require_world_age[]
-    if world == typemax(UInt)
-        world = get_world_counter()
-    end
-    return invoke_in_world(world, __require, into, mod)
-end
-
-function __require(into::Module, mod::Symbol)
     if into === __toplevel__ && generating_output(#=incremental=#true)
         error("`using/import $mod` outside of a Module detected. Importing a package outside of a module \
          is not allowed during package precompilation.")
@@ -2459,14 +2449,11 @@ function collect_manifest_warnings()
     return msg
 end
 
-function require(uuidkey::PkgId)
-    world = _require_world_age[]
-    if world == typemax(UInt)
-        world = get_world_counter()
-    end
-    return invoke_in_world(world, __require, uuidkey)
-end
-__require(uuidkey::PkgId) = @lock require_lock _require_prelocked(uuidkey)
+# __require(uuidkey::PkgId) = @lock require_lock _require_prelocked(uuidkey)
+require(uuidkey::PkgId) = @lock require_lock _require_prelocked(uuidkey)
+
+const REPL_PKGID = PkgId(UUID("3fa0cd96-eef1-5676-8a61-b3b8758bbffb"), "REPL")
+
 function _require_prelocked(uuidkey::PkgId, env=nothing)
     assert_havelock(require_lock)
     m = start_loading(uuidkey, UInt128(0), true)