PPC: [regexp] correctly advance zero length matches for global/unicode.

src/regexp/ppc/regexp-macro-assembler-ppc.cc

Index: src/regexp/ppc/regexp-macro-assembler-ppc.cc
diff --git a/src/regexp/ppc/regexp-macro-assembler-ppc.cc b/src/regexp/ppc/regexp-macro-assembler-ppc.cc
index f3ddf7bf986372ec136f75b12436c56a2d1fee32..4f2e0124c4d74ad92d439d9f1250d6048478f4b7 100644
--- a/src/regexp/ppc/regexp-macro-assembler-ppc.cc
+++ b/src/regexp/ppc/regexp-macro-assembler-ppc.cc
@@ -845,8 +845,11 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
           __ 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);