Define SUFFIX_PERL

This allows Perl files with filetype 102 to be referenced identically whether
native or cross-compiling (it expands to an empty string when used natively).

GNUmakefiles/StdTools

@@ -13,6 +13,7 @@ SUFFIX_ABSOLUTE = ,ff8
 SUFFIX_OBEY     = ,feb
 SUFFIX_DEBIMAGE = ,fd3
 endif
+SUFFIX_PERL     = ,102
 SUFFIX_HEADER   = .h
 
 #