Revert "CMake: Don't create symlinks on unsupporting file systems (#539)"

As noted in #539, the symlink check was to support compiling raylib on
VirtualBox vboxfs as no symlinks are supported there.

With me using Linux as daily driver outside VirtualBox now, this 'feature'
is most likely unused by anyone, but still annoys other users (#791).
Just revert it and be done with it. If there are really others building
raylib on vboxfs or a similarly crippled file system under Linux, they
should now step forward when their build breaks.

This reverts commit b8ca51fd01.

.gitignore

@@ -104,7 +104,6 @@ CMakeCache.txt
 CMakeFiles
 CMakeScripts
 Testing
-TestingIfSymlinkWorks
 cmake_install.cmake
 install_manifest.txt
 compile_commands.json

CMakeLists.txt

@@ -22,8 +22,6 @@ add_if_flag_compiles(-Werror=implicit-function-declaration CMAKE_C_FLAGS)
 # src/external/jar_xm.h does shady stuff
 add_if_flag_compiles(-fno-strict-aliasing CMAKE_C_FLAGS)
 
-include(CheckFileSystemSymlinkSupport)
-
 if (ENABLE_ASAN)
     add_if_flag_compiles(-fno-omit-frame-pointer CMAKE_C_FLAGS CMAKE_LINKER_FLAGS)
     add_if_flag_compiles(-fsanitize=address CMAKE_C_FLAGS CMAKE_LINKER_FLAGS)

cmake/CheckFileSystemSymlinkSupport.cmake

@@ -1,14 +0,0 @@
-# Populates a ${FILESYSTEM_LACKS_SYMLINKS} variable
-message(STATUS "Testing if file system supports symlinks")
-execute_process(
-  COMMAND ${CMAKE_COMMAND} -E create_symlink CMakeLists.txt "${CMAKE_CURRENT_BINARY_DIR}/TestingIfSymlinkWorks"
-    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-    RESULT_VARIABLE FILESYSTEM_LACKS_SYMLINKS
-    ERROR_QUIET
-)
-If (FILESYSTEM_LACKS_SYMLINKS)
-  message(STATUS "Testing if file system supports symlinks -- unsupported")
-else()
-  message(STATUS "Testing if file system supports symlinks -- supported")
-endif()
-

src/CMakeLists.txt

@@ -208,16 +208,10 @@ if(SHARED)
   if (${PLATFORM} MATCHES "Desktop")
     target_link_libraries(raylib glfw)
   endif()
-  if (UNIX AND ${FILESYSTEM_LACKS_SYMLINKS})
-    MESSAGE(WARNING "Can't version UNIX shared library on file system without symlink support")
-  else()
-      set_target_properties(raylib PROPERTIES
-          VERSION   ${PROJECT_VERSION}
-          SOVERSION ${API_VERSION}
-      )
-  endif()
   set_target_properties(raylib PROPERTIES
       PUBLIC_HEADER "raylib.h"
+      VERSION   ${PROJECT_VERSION}
+      SOVERSION ${API_VERSION}
   )
 
   if (WIN32)