Provide a port of cpu related code to posix, and linux.

Properly set this up in our build environment.
	Change on 2014/12/23 by ctiller <ctiller@google.com>
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=82725899
diff --git a/build.json b/build.json
index 526b2bf..1db8dc4 100644
--- a/build.json
+++ b/build.json
@@ -18,6 +18,7 @@
         "src/core/support/alloc.c",
         "src/core/support/cancellable.c",
         "src/core/support/cmdline.c",
+        "src/core/support/cpu_linux.c",
         "src/core/support/cpu_posix.c",
         "src/core/support/histogram.c",
         "src/core/support/host_port.c",