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/x87/assembler-x87.cc b/src/x87/assembler-x87.cc
index 5391948..66fda57 100644
--- a/src/x87/assembler-x87.cc
+++ b/src/x87/assembler-x87.cc
@@ -674,6 +674,11 @@
   emit_operand(reg, op);
 }
 
+void Assembler::cmp(const Operand& op, Register reg) {
+  EnsureSpace ensure_space(this);
+  EMIT(0x39);
+  emit_operand(reg, op);
+}
 
 void Assembler::cmp(const Operand& op, const Immediate& imm) {
   EnsureSpace ensure_space(this);