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/mips/simulator-mips.h b/src/mips/simulator-mips.h
index 8efe0bb..e1c42fd 100644
--- a/src/mips/simulator-mips.h
+++ b/src/mips/simulator-mips.h
@@ -359,13 +359,13 @@
 
   // Compact branch guard.
   void CheckForbiddenSlot(int32_t current_pc) {
-    Instruction* instr_aftter_compact_branch =
+    Instruction* instr_after_compact_branch =
         reinterpret_cast<Instruction*>(current_pc + Instruction::kInstrSize);
-    if (instr_aftter_compact_branch->IsForbiddenInBranchDelay()) {
+    if (instr_after_compact_branch->IsForbiddenAfterBranch()) {
       V8_Fatal(__FILE__, __LINE__,
                "Error: Unexpected instruction 0x%08x immediately after a "
                "compact branch instruction.",
-               *reinterpret_cast<uint32_t*>(instr_aftter_compact_branch));
+               *reinterpret_cast<uint32_t*>(instr_after_compact_branch));
     }
   }