Fixed bug 4027 - CheckLibSampleRate macro in sdlchecks.cmake never defines HAVE_LIBSAMPLERATE{,_SHARED}, so they're always reported as disabled by MESSAGE_TESTED_OPTION macro in macros.cmake

cmake/sdlchecks.cmake

@@ -354,12 +354,14 @@ macro(CheckLibSampleRate)
   if(LIBSAMPLERATE)
     check_include_file(samplerate.h HAVE_LIBSAMPLERATE_H)
     if(HAVE_LIBSAMPLERATE_H)
+      set(HAVE_LIBSAMPLERATE TRUE)
       if(LIBSAMPLERATE_SHARED)
         if(NOT HAVE_DLOPEN)
           message_warn("You must have SDL_LoadObject() support for dynamic libsamplerate loading")
         else()
           FindLibraryAndSONAME("samplerate")
           set(SDL_LIBSAMPLERATE_DYNAMIC "\"${SAMPLERATE_LIB_SONAME}\"")
+          set(HAVE_LIBSAMPLERATE_SHARED TRUE)
         endif()
       else()
         list(APPEND EXTRA_LDFLAGS -lsamplerate)