'javap -v' on protocol class reveals no source file

Through "javap -v" I can find source filename information in Clojure-generated datatype class files but not in protocol ones.

Approach: In gen-interface, if the *source-path* indicates this is not a REPL-generated interface, invoke the proper ASM method to set the source file. Per JVM expectations, this is the actual file name, not the file path.

Patch: CLJ-1645-protocol-class-has-no-source-file-information-w-repl.patch

Screened by: Alex Miller