Utilize the new "all" ARCHITECTURES keyword in most recipes. (#6189)

x86_64 is used as a baseline: the "x86_64" entry, whatever status it has,
is transformed into "all", and then the other entries in ARCHITECTURES
either dropped or rearranged appropriately.

dev-lang/python/python-2.7.18.recipe

@@ -15,7 +15,7 @@ CHECKSUM_SHA256="b62c0e7937551d0cc02b8fd5cb0f544f9405bafc9a54d3808ed4594812edef4
 SOURCE_DIR="Python-$portVersion"
 PATCHES="python-$portVersion.patchset"
 
-ARCHITECTURES="x86_gcc2 x86 x86_64 sparc m68k"
+ARCHITECTURES="all"
 
 GLOBAL_WRITABLE_FILES="
 	non-packaged/lib/python2.7/site-packages directory keep-old

dev-lang/python/python3-3.7.10.recipe

@@ -20,7 +20,7 @@ if [ "$secondaryArchSuffix" = _x86 ] ; then
 	"
 fi
 
-ARCHITECTURES=" !x86_gcc2 x86 x86_64"
+ARCHITECTURES="all !x86_gcc2"
 SECONDARY_ARCHITECTURES="x86"
 
 # On x86_gcc2 we don't want to install the commands in bin/<arch>/, but in bin/.

dev-lang/python/python36-3.6.12.recipe

@@ -20,7 +20,7 @@ if [ "$secondaryArchSuffix" = _x86 ] ; then
 	"
 fi
 
-ARCHITECTURES=" !x86_gcc2 x86 x86_64"
+ARCHITECTURES="all !x86_gcc2"
 SECONDARY_ARCHITECTURES="x86"
 
 # On x86_gcc2 we don't want to install the commands in bin/<arch>/, but in bin/.

dev-lang/python/python38-3.8.8.recipe

@@ -20,7 +20,7 @@ if [ "$secondaryArchSuffix" = _x86 ] ; then
 	"
 fi
 
-ARCHITECTURES=" !x86_gcc2 ?x86 x86_64"
+ARCHITECTURES="all !x86_gcc2 ?x86"
 SECONDARY_ARCHITECTURES="x86"
 
 # On x86_gcc2 we don't want to install the commands in bin/<arch>/, but in bin/.

dev-lang/python/python39-3.9.5.recipe

@@ -20,7 +20,7 @@ if [ "$secondaryArchSuffix" = _x86 ] ; then
 	"
 fi
 
-ARCHITECTURES=" !x86_gcc2 ?x86 x86_64 arm arm64 riscv64"
+ARCHITECTURES="all !x86_gcc2 ?x86"
 SECONDARY_ARCHITECTURES="x86"
 
 # On x86_gcc2 we don't want to install the commands in bin/<arch>/, but in bin/.