Revert "Revert "Upgrade to 5.0.71.48"" DO NOT MERGE

This reverts commit f2e3994fa5148cc3d9946666f0b0596290192b0e,
and updates the x64 makefile properly so it doesn't break that
build.

FPIIM-449

Change-Id: Ib83e35bfbae6af627451c926a9650ec57c045605
(cherry picked from commit 109988c7ccb6f3fd1a58574fa3dfb88beaef6632)
diff --git a/src/base/cpu.cc b/src/base/cpu.cc
index 692494a..777f379 100644
--- a/src/base/cpu.cc
+++ b/src/base/cpu.cc
@@ -312,6 +312,8 @@
       architecture_(0),
       variant_(-1),
       part_(0),
+      icache_line_size_(UNKNOWN_CACHE_LINE_SIZE),
+      dcache_line_size_(UNKNOWN_CACHE_LINE_SIZE),
       has_fpu_(false),
       has_cmov_(false),
       has_sahf_(false),
@@ -644,9 +646,16 @@
       if (n == 0 || entry.a_type == AT_NULL) {
         break;
       }
-      if (entry.a_type == AT_PLATFORM) {
-        auxv_cpu_type = reinterpret_cast<char*>(entry.a_un.a_val);
-        break;
+      switch (entry.a_type) {
+        case AT_PLATFORM:
+          auxv_cpu_type = reinterpret_cast<char*>(entry.a_un.a_val);
+          break;
+        case AT_ICACHEBSIZE:
+          icache_line_size_ = entry.a_un.a_val;
+          break;
+        case AT_DCACHEBSIZE:
+          dcache_line_size_ = entry.a_un.a_val;
+          break;
       }
     }
     fclose(fp);