I believe that sometimes you can use SRAM for implementing register files .. registers files are more of a concept .. try Artisan memory compiler to get more information regarding what ur specifically looking for ..
SRAM is an array of registers that are interfaced to the outside world through address and data buses, with single port and dual port configurations being the most common.
A register file(RF) is also bunch of registers(usually small number of them) but has many ports with predifined access. For example the most basic RF can contain two read ports and one write port.