Fixes an issue where compound assignments containing strings cause an error at runtime.
Call string.Concat if either the left or right side is something other than string.
Convert the right side to string in advance if that is other than string and is a constant.
Fixes an issue where compound assignments containing strings cause an error at runtime. Call string.Concat if either the left or right side is something other than string. Convert the right side to string in advance if that is other than string and is a constant.