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/Makefile b/Makefile
index fd4aa8a..60bfec3 100644
--- a/Makefile
+++ b/Makefile
@@ -1056,6 +1056,7 @@
     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 \