Remove unsafe_pure from Val

Author: helgee

base/essentials.jl

@@ -700,7 +700,7 @@ julia> f(Val(true))
 struct Val{x}
 end
 
-Val(x) = (@_unsafe_pure_meta; Val{x}())
+Val(x) = Val{x}()
 
 """
     invokelatest(f, args...; kwargs...)

doc/src/manual/types.md

@@ -1383,7 +1383,7 @@ for cases where you don't need a more elaborate hierarchy.
 julia> struct Val{x}
        end
 
-julia> Base.@unsafe_pure Val(x) = Val{x}()
+julia> Val(x) = Val{x}()
 Val
 ```