This fixes the case when an integer is used as the initializer, such as:
struct W { static const char w = 100; };
The "valuetype" attribute has been added to the "cdecl" Node which enables
us to distinguish the declared type from the type of the initializer.
Since Lua 5.3 the "%c" format character in lua_pushfstring will produce
the string "<\XXX>" (XXX being a decimal code sequence) when
given unprintable characters.
Use lua_pushlstring instead to reproduce the old behavior.
