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/regexp/ppc/regexp-macro-assembler-ppc.cc b/src/regexp/ppc/regexp-macro-assembler-ppc.cc
index f3ddf7b..c05c580 100644
--- a/src/regexp/ppc/regexp-macro-assembler-ppc.cc
+++ b/src/regexp/ppc/regexp-macro-assembler-ppc.cc
@@ -225,9 +225,8 @@
   BranchOrBacktrack(eq, on_equal);
 }
 
-
 void RegExpMacroAssemblerPPC::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, Label* on_no_match) {
+    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
   Label fallthrough;
   __ LoadP(r3, register_location(start_reg), r0);  // Index of start of capture
   __ LoadP(r4, register_location(start_reg + 1), r0);  // Index of end
@@ -322,7 +321,7 @@
     //   r3: Address byte_offset1 - Address captured substring's start.
     //   r4: Address byte_offset2 - Address of current character position.
     //   r5: size_t byte_length - length of capture in bytes(!)
-    //   r6: Isolate* isolate
+    //   r6: Isolate* isolate or 0 if unicode flag.
 
     // Address of start of capture.
     __ add(r3, r3, end_of_input_address());
@@ -336,7 +335,14 @@
       __ sub(r4, r4, r25);
     }
     // Isolate.
-    __ mov(r6, Operand(ExternalReference::isolate_address(isolate())));
+#ifdef V8_I18N_SUPPORT
+    if (unicode) {
+      __ li(r6, Operand::Zero());
+    } else  // NOLINT
+#endif      // V8_I18N_SUPPORT
+    {
+      __ mov(r6, Operand(ExternalReference::isolate_address(isolate())));
+    }
 
     {
       AllowExternalCallThatCantCauseGC scope(masm_);
@@ -845,8 +851,11 @@
           __ cmpi(current_input_offset(), Operand::Zero());
           __ beq(&exit_label_);
           // Advance current position after a zero-length match.
+          Label advance;
+          __ bind(&advance);
           __ addi(current_input_offset(), current_input_offset(),
                   Operand((mode_ == UC16) ? 2 : 1));
+          if (global_unicode()) CheckNotInSurrogatePair(0, &advance);
         }
 
         __ b(&load_char_start_regexp);