Fix shared library building failure on Windows with non MSVC

For example, now we can built shared library on Window with MinGW.

This changes improve features added in #1467.

CMakeLists.txt

@@ -131,16 +131,15 @@ if(NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
     list(APPEND SPDLOG_SRCS src/fmt.cpp)
 endif()
 
-if(WIN32 AND SPDLOG_BUILD_SHARED)
-    list(APPEND SPDLOG_SRCS ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
-endif()
-
 if(SPDLOG_BUILD_SHARED)
+    if(WIN32)
+        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/version.rc.in ${CMAKE_CURRENT_BINARY_DIR}/version.rc @ONLY)
+        list(APPEND SPDLOG_SRCS ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
+    endif()
     add_library(spdlog SHARED ${SPDLOG_SRCS} ${SPDLOG_ALL_HEADERS})
     target_compile_definitions(spdlog PUBLIC SPDLOG_SHARED_LIB)
-    if(WIN32)
+    if(MSVC)
         target_compile_options(spdlog PUBLIC /wd4251 /wd4275)
-        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/version.rc.in ${CMAKE_CURRENT_BINARY_DIR}/version.rc @ONLY)
     endif()
     if(NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
         target_compile_definitions(spdlog PRIVATE FMT_EXPORT PUBLIC FMT_SHARED)

cmake/version.rc.in

@@ -1,5 +1,5 @@
 #define APSTUDIO_READONLY_SYMBOLS
-#include "winres.h"
+#include <windows.h>
 #undef APSTUDIO_READONLY_SYMBOLS
 
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US