arch_requirement: update and add to JSON representation of formulae

Library/Homebrew/formula.rb

@@ -1772,7 +1772,7 @@ class Formula
         "name"     => req.name,
         "cask"     => req.cask,
         "download" => req.download,
-        "version"  => req.try(:version),
+        "version"  => req.try(:version) || req.try(:arch),
         "contexts" => req.tags,
       }
     end

Library/Homebrew/requirements/arch_requirement.rb

@@ -9,6 +9,8 @@ require "requirement"
 class ArchRequirement < Requirement
   fatal true
 
+  attr_reader :arch
+
   def initialize(tags)
     @arch = tags.shift
     super(tags)
@@ -16,8 +18,8 @@ class ArchRequirement < Requirement
 
   satisfy(build_env: false) do
     case @arch
-    when :x86_64 then Hardware::CPU.is_64_bit?
-    when :intel, :ppc then Hardware::CPU.type == @arch
+    when :x86_64 then Hardware::CPU.intel? && Hardware::CPU.is_64_bit?
+    when :arm, :intel, :ppc then Hardware::CPU.type == @arch
     end
   end