pure: Set supported_archs to exclude arm64

See: https://github.com/agraef/pure-lang/issues/42

_resources/port1.0/group/pure-1.0.tcl

@@ -26,6 +26,9 @@ proc pure.setup {module module_version} {
 
     depends_lib-append          port:pure
 
+    # llvm-3.4 and therefore pure doesn't support arm64
+    supported_archs             ppc ppc64 i386 x86_64
+
     use_configure               no
 
     build.args-append           PUREC_FLAGS=-mcpu=generic

lang/pure/Portfile

@@ -38,6 +38,9 @@ set llvm_version        3.4
 set llvm_prefix         ${prefix}/libexec/llvm-${llvm_version}
 configure.env           PATH=${llvm_prefix}/bin:$env(PATH)
 
+# llvm-3.4 doesn't support arm64
+supported_archs         ppc ppc64 i386 x86_64
+
 if {${name} eq ${subport}} {
     revision                    4