bpart: Start enforcing min_world for global variable definitions (JuliaLang#57150)

This is the analog of JuliaLang#57102 for global variables. Unlike for consants,
there is no automatic global backdate mechanism. The reasoning for this
is that global variables can be declared at any time, unlike constants
which can only be decalared once their value is available. As a result
code patterns using `Core.eval` to declare globals are rarer and likely
incorrect.

Author: Keno

test/abioverride.jl

@@ -46,7 +46,7 @@ let world = Base.tls_world_age()
     global new_ci = Core.CodeInstance(Core.ABIOverride(Tuple{typeof(myplus), Int}, mi),
         #=owner=#SecondArgConstOverride(1), new_source.rettype, Any#=new_source.exctype is missing=#,
         #=inferred_const=#nothing, #=code=#nothing, #=const_flags=#Int32(0),
-        new_source.min_world, new_source.max_world, #=new_source.ipo_purity_bits is missing=#UInt32(0),
+        new_source.min_world, typemax(UInt), #=new_source.ipo_purity_bits is missing=#UInt32(0),
         #=analysis_results=#nothing, new_source.debuginfo, new_source.edges)
 
     # Poke the CI into the global cache