build: resolve mapierr.hpp build failure under -DCOMPILE_DIAG

```
mapierr.hpp:439:18: error: variable ‘GX_EXPORT ec_error_t’ has
initializer but incomplete type
  439 | struct GX_EXPORT ec_error_t {
```

Fixes: gromox-2.44-97-g5bcce22bf

Author: jengelh

include/gromox/defs.h

@@ -8,7 +8,6 @@
 #endif
 #include <string>
 #include <type_traits>
-#include <gromox/mapierr.hpp>
 #define FMODE_PRIVATE 0660U
 #define FMODE_PUBLIC 0666U
 #define SOCKET_TIMEOUT 60
@@ -32,6 +31,8 @@
 	inline bool empty() const { return (count) == 0; } \
 	inline void push_back(const value_type &v) { (memb)[(count)++] = v; }
 
+#include <gromox/mapierr.hpp>
+
 /*
  * The timezone column in the user database ought to be never empty. Having an
  * unusual fallback offset means that missing TZ problems will readily be

lib/rfbl.cpp

@@ -1787,7 +1787,12 @@ errno_t canonical_hostname(std::string &out) try
 
 int ece2nerrno(ec_error_t e)
 {
-	switch (e) {
+#ifdef COMPILE_DIAG
+	switch (static_cast<uint32_t>(e))
+#else
+	switch (e)
+#endif
+	{
 	case ecSuccess: return 0;
 	case ecMAPIOOM: [[fallthrough]];
 	case ecServerOOM: return -ENOMEM;