GUIStyle.fontSize is 0 as opposed to 12 in new versions.
EditorGUILayout.Space does not take any parameters.
ShaderCompilerData.buildTarget has been added recently and backported to older versions of Unity so we have to use Reflection to see if it's available.
Description
Fix several compilation issues in Unity 2018
Notes
GUIStyle.fontSizeis 0 as opposed to 12 in new versions.EditorGUILayout.Spacedoes not take any parameters.ShaderCompilerData.buildTargethas been added recently and backported to older versions of Unity so we have to use Reflection to see if it's available.