only use cdecl calling convention on i386 architectures

This removes a warning when compiling on x64 plattforms.
The C# DllImportAttribute ignores this calling canvention as well, but dosn't give a warning.

rcldotnet/rcldotnet_macros.h

@@ -18,11 +18,19 @@
 #if defined(_MSC_VER)
     #define RCLDOTNET_EXPORT __declspec(dllexport)
     #define RCLDOTNET_IMPORT __declspec(dllimport)
-    #define RCLDOTNET_CDECL __cdecl
+    #if defined(_M_IX86)
+        #define RCLDOTNET_CDECL __cdecl
+    #else
+        #define RCLDOTNET_CDECL
+    #endif
 #elif defined(__GNUC__)
     #define RCLDOTNET_EXPORT __attribute__((visibility("default")))
     #define RCLDOTNET_IMPORT
-    #define RCLDOTNET_CDECL __attribute__((__cdecl__))
+    #if defined(__i386__)
+        #define RCLDOTNET_CDECL __attribute__((__cdecl__))
+    #else
+        #define RCLDOTNET_CDECL
+    #endif
 #else
     #define RCLDOTNET_EXPORT
     #define RCLDOTNET_IMPORT

rosidl_generator_dotnet/resource/msg.h.em

@@ -18,12 +18,20 @@ msg_prefix = "RCLDOTNET_{0}_{1}_{2}".format(package_name, '_'.join(message.struc
     //  Microsoft
     #define @(msg_prefix)_EXPORT __declspec(dllexport)
     #define @(msg_prefix)_IMPORT __declspec(dllimport)
-    #define @(msg_prefix)_CDECL __cdecl
+    #if defined(_M_IX86)
+        #define @(msg_prefix)_CDECL __cdecl
+    #else
+        #define @(msg_prefix)_CDECL
+    #endif
 #elif defined(__GNUC__)
     //  GCC
     #define @(msg_prefix)_EXPORT __attribute__((visibility("default")))
     #define @(msg_prefix)_IMPORT
-    #define @(msg_prefix)_CDECL __attribute__((__cdecl__))
+    #if defined(__i386__)
+        #define @(msg_prefix)_CDECL __attribute__((__cdecl__))
+    #else
+        #define @(msg_prefix)_CDECL
+    #endif
 #else
     //  do nothing and hope for the best?
     #define @(msg_prefix)_EXPORT

rosidl_generator_dotnet/resource/srv.h.em

@@ -7,12 +7,20 @@ srv_prefix = "RCLDOTNET_{0}_{1}_{2}".format(package_name, '_'.join(service.names
     //  Microsoft
     #define @(srv_prefix)_EXPORT __declspec(dllexport)
     #define @(srv_prefix)_IMPORT __declspec(dllimport)
-    #define @(srv_prefix)_CDECL __cdecl
+    #if defined(_M_IX86)
+        #define @(srv_prefix)_CDECL __cdecl
+    #else
+        #define @(srv_prefix)_CDECL
+    #endif
 #elif defined(__GNUC__)
     //  GCC
     #define @(srv_prefix)_EXPORT __attribute__((visibility("default")))
     #define @(srv_prefix)_IMPORT
-    #define @(srv_prefix)_CDECL __attribute__((__cdecl__))
+    #if defined(__i386__)
+        #define @(srv_prefix)_CDECL __attribute__((__cdecl__))
+    #else
+        #define @(srv_prefix)_CDECL
+    #endif
 #else
     //  do nothing and hope for the best?
     #define @(srv_prefix)_EXPORT