1. At a computer system including a processor and a memory, a computer-implemented method for tracking variable location information in optimized code, the method comprising: an act of receiving a portion of source code at a compiler, wherein the compiler is configured to compile and optimize the source code for execution; an act of tagging one or more selected variables in the source code with a tag, wherein the tag is configured to provide location information for the variable; an act of the compiler optimizing the received portion of source code, wherein optimizing at least includes changing one or more of the tagged variables; an act of tracking the tagged variables as the variables are changed by the compiler during code optimization; and an act of persisting the variable location information, such that the persisted variable location information is available to one or more other compiler components.