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/test/cctest/compiler/value-helper.h b/test/cctest/compiler/value-helper.h
index cbde9a7..83cd33c 100644
--- a/test/cctest/compiler/value-helper.h
+++ b/test/cctest/compiler/value-helper.h
@@ -312,6 +312,23 @@
 
 #define FOR_UINT32_SHIFTS(var) for (uint32_t var = 0; var < 32; var++)
 
+// TODO(bmeurer): Drop this crap once we switch to GTest/Gmock.
+static inline void CheckFloatEq(volatile float x, volatile float y) {
+  if (std::isnan(x)) {
+    CHECK(std::isnan(y));
+  } else {
+    CHECK_EQ(x, y);
+  }
+}
+
+static inline void CheckDoubleEq(volatile double x, volatile double y) {
+  if (std::isnan(x)) {
+    CHECK(std::isnan(y));
+  } else {
+    CHECK_EQ(x, y);
+  }
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8