Upgrade V8 to 5.1.281.57  DO NOT MERGE

FPIIM-449

Change-Id: Id981b686b4d587ac31697662eb98bb34be42ad90
(cherry picked from commit 3b9bc31999c9787eb726ecdbfd5796bfdec32a18)
diff --git a/src/ppc/assembler-ppc.cc b/src/ppc/assembler-ppc.cc
index aed149b..507eec1 100644
--- a/src/ppc/assembler-ppc.cc
+++ b/src/ppc/assembler-ppc.cc
@@ -849,6 +849,10 @@
   xo_form(EXT2 | ADDCX, dst, src1, src2, o, r);
 }
 
+void Assembler::adde(Register dst, Register src1, Register src2, OEBit o,
+                     RCBit r) {
+  xo_form(EXT2 | ADDEX, dst, src1, src2, o, r);
+}
 
 void Assembler::addze(Register dst, Register src1, OEBit o, RCBit r) {
   // a special xo_form
@@ -861,12 +865,15 @@
   xo_form(EXT2 | SUBFX, dst, src2, src1, o, r);
 }
 
-
-void Assembler::subfc(Register dst, Register src1, Register src2, OEBit o,
-                      RCBit r) {
+void Assembler::subc(Register dst, Register src1, Register src2, OEBit o,
+                     RCBit r) {
   xo_form(EXT2 | SUBFCX, dst, src2, src1, o, r);
 }
 
+void Assembler::sube(Register dst, Register src1, Register src2, OEBit o,
+                     RCBit r) {
+  xo_form(EXT2 | SUBFEX, dst, src2, src1, o, r);
+}
 
 void Assembler::subfic(Register dst, Register src, const Operand& imm) {
   d_form(SUBFIC, dst, src, imm.imm_, true);