fix invalidations related to ismutable

Author: ranocha

base/reflection.jl

@@ -627,7 +627,9 @@ true
 !!! compat "Julia 1.5"
     This function requires at least Julia 1.5.
 """
-ismutable(@nospecialize(x)) = (@_total_meta; typeof(x).name.flags & 0x2 == 0x2)
+ismutable(@nospecialize(x)) = (@_total_meta; (typeof(x).name::Core.TypeName).flags & 0x2 == 0x2)
+# The type assertion above is required to fix some invalidations.
+# See also https://github.com/JuliaLang/julia/issues/52134
 
 """
     ismutabletype(T) -> Bool