dev-lang/perl: Stop treating minor devrels as ABI compatible

Development releases of Perl are not ABI-intercompatible with each
other, regardless of *actual* ABI compat, as Perl itself enforces
minor-version breaks in XS code.

Hence, this commit:
1. Ensures that development releases use the full 5.xx.yyy for the
   subslot
2. Ensures the arch-abi-path from older 5.ODD series is not shared
   with newer 5.ODD

Package-Manager: Portage-2.3.4, Repoman-2.3.2

dev-lang/perl/perl-5.26.9999.ebuild

@@ -15,19 +15,22 @@ if [[ "${PV##*.}" == "9999" ]]; then
  # Include more versions for blead releases
  # for circular reasons
  # Greatest first, don't include yourself
- PERL_BIN_OLDVERSEN="5.25.11"
+ PERL_BIN_OLDVERSEN=""
  PERL_OLDVERSEN="5.25.11 5.24.2 5.24.1 5.24.0 5.22.3 5.22.2 5.22.1 5.22.0"
  DIST_VERSION=5.25.12
  SHORT_PV="${DIST_VERSION%.*}"
+ # Devel Releases are not ABI-intercompatible
+ SUBSLOT="${DIST_VERSION}"
  MY_P="perl-${DIST_VERSION/_rc/-RC}"
  PATCH_BASE="perl-5.25.11-patches-${PATCH_VER}"
  MY_PV="${DIST_VERSION%_rc*}"
 else
- PERL_BIN_OLDVERSEN="5.25.11"
+ PERL_BIN_OLDVERSEN=""
  # Compat reasons
  PERL_OLDVERSEN="5.25.11"
  # First 2 digits only
  SHORT_PV="${PV%.*}"
+ SUBSLOT="${SHORT_PV}"
  MY_P="perl-${PV/_rc/-RC}"
  PATCH_BASE="${MY_P}-patches-${PATCH_VER}"
  MY_PV="${PV%_rc*}"
@@ -46,7 +49,7 @@ SRC_URI="
 HOMEPAGE="http://www.perl.org/"
 
 LICENSE="|| ( Artistic GPL-1+ )"
-SLOT="0/${SHORT_PV}"
+SLOT="0/${SUBSLOT}"
 
 if [[ "${PV##*.}" != "9999" ]]; then
 KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86 ~ppc-aix ~x64-cygwin ~amd64-fbsd ~x86-fbsd ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~x86-macos ~m68k-mint ~sparc-solaris ~sparc64-solaris ~x64-solaris ~x86-solaris"