fix: add hxbit + stdio.h compatibility (#393)

src/hlc.h

@@ -47,6 +47,7 @@
 #undef CW_USEDEFAULT
 #undef HIDDEN
 #undef RESIZABLE
+#undef __SIGN
 
 // disable some warnings triggered by HLC code generator
 
@@ -86,4 +87,4 @@ extern void hl_entry_point();
 #define HL__ENUM_CONSTRUCT__	hl_type *t; int index;
 #define HL__ENUM_INDEX__(v)		((venum*)(v))->index
 
-#endif
+#endif