linux/hardware/cpu: import family from Linuxbrew.

Library/Homebrew/extend/os/linux/hardware/cpu.rb

@@ -18,9 +18,51 @@ module Hardware
       end
 
       def family
-        cpuinfo[/^cpu family\s*: ([0-9]+)/, 1].to_i
+        return :arm if arm?
+        return :dunno unless intel?
+        # See https://software.intel.com/en-us/articles/intel-architecture-and-processor-identification-with-cpuid-model-and-family-numbers
+        cpu_family = cpuinfo[/^cpu family\s*: ([0-9]+)/, 1].to_i
+        cpu_model = cpuinfo[/^model\s*: ([0-9]+)/, 1].to_i
+        cpu_family_model = "0x" + ((cpu_family << 8) | cpu_model).to_s(16)
+        case cpu_family
+        when 0x06
+          case cpu_model
+          when 0x3a, 0x3e
+            :ivybridge
+          when 0x2a, 0x2d
+            :sandybridge
+          when 0x25, 0x2c, 0x2f
+            :westmere
+          when 0x1e, 0x1a, 0x2e
+            :nehalem
+          when 0x17, 0x1d
+            :penryn
+          when 0x0f, 0x16
+            :merom
+          when 0x0d
+            :dothan
+          when 0x36, 0x26, 0x1c
+            :atom
+          when 0x3c, 0x3f, 0x46
+            :haswell
+          when 0x3d, 0x47, 0x4f, 0x56
+            :broadwell
+          else
+            cpu_family_model
+          end
+        when 0x0f
+          case cpu_model
+          when 0x06
+            :presler
+          when 0x03, 0x04
+            :prescott
+          else
+            cpu_family_model
+          end
+        else
+          cpu_family_model
+        end
       end
-      alias_method :intel_family, :family
 
       def cores
         cpuinfo.scan(/^processor/).size