cc_configure: correctly detect 32/64 bits CPU for Linux

It is now consistent with CPU.java

Fixes #1251.

--
MOS_MIGRATED_REVID=122036487
diff --git a/tools/cpp/cc_configure.bzl b/tools/cpp/cc_configure.bzl
index 7f33475..226f10f 100644
--- a/tools/cpp/cc_configure.bzl
+++ b/tools/cpp/cc_configure.bzl
@@ -105,7 +105,7 @@
     return "x64_windows"
   # Use uname to figure out whether we are on x86_32 or x86_64
   result = repository_ctx.execute(["uname", "-m"])
-  return "piii" if result.stdout.strip() == "i386" else "k8"
+  return "k8" if result.stdout.strip() in ["amd64", "x86_64", "x64"] else "piii"
 
 
 _INC_DIR_MARKER_BEGIN = "#include <...>"