1. A method of resolving references in ahead-of-time (AOT) compiled code, the method comprising: loading into a class loader AOT code comprising a header as a relocation record specifying a set of classes, a class field and class method instance references that are as-yet unresolved at load time of the AOT code and class, class field and class method instance references that have been resolved as of the load time of the AOT code; updating the AOT code, at loading time, into updated AOT code for already resolved class references with specific addresses being provided at offsets listed in the relocation record; and, executing the updated AOT code to resolve remaining unresolved class references into the updated AOT code to produce executable AOT code.