Print unsigned integers as hex literals with apt width.

j/show.j

@@ -8,7 +8,14 @@ show(tn::TypeName) = show(tn.name)
 show(::Nothing) = print("nothing")
 show(b::Bool) = print(b ? "true" : "false")
 show(n::Int)  = show(int64(n))
-show(n::Uint) = show(uint64(n))
+
+function show_trailing_hex(n::Uint64, ndig::Int)
+    for s = ndig-1:-1:0
+        d = (n >> 4*s) & uint64(0xf)
+        print("0123456789abcdef"[long(d+1)])
+    end
+end
+show(n::Uint) = (print("0x"); show_trailing_hex(uint64(n),sizeof(n)<<1))
 
 show_float64(f::Float64, ndig) =
     ccall(:jl_show_float, Void, (Float64, Int32), f, int32(ndig))

src/builtins.c

@@ -1335,7 +1335,6 @@ void jl_init_builtins(void)
 
     add_builtin_method1(jl_show_gf, (jl_type_t*)jl_any_type,         jl_f_show_any);
     add_builtin_method1(jl_show_gf, (jl_type_t*)jl_int64_type,       jl_f_show_int64);
-    add_builtin_method1(jl_show_gf, (jl_type_t*)jl_uint64_type,      jl_f_show_uint64);
 
     jl_convert_gf = jl_new_generic_function(jl_symbol("convert"));
     jl_add_method(jl_convert_gf,

test/core.j

@@ -602,7 +602,7 @@ end
 @assert parse_hex("DeadBeef") == 3735928559
 
 # bits types, printing numbers
-@assert string(uint32(-1)) == "4294967295"
+@assert string(uint32(-1)) == "0xffffffff"
 if WORD_SIZE == 64
     @assert isa((()->box(Ptr{Int8},unbox64(int64(0))))(), Ptr{Int8})
 else