Provides a little more info on enums for simple 'p <enum>' cases; keeps 
the old format for complex cases like structs and arrays:

(gdb) p e
$1 = Val1 = (enum E)56
(gdb) p ea
$2 = {Val1, Val2, Val1}
(gdb) p es
$3 = {v = 5, e = Val2}
(gdb)