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

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

Index: src/regexp/arm/regexp-macro-assembler-arm.cc
diff --git a/src/regexp/arm/regexp-macro-assembler-arm.cc b/src/regexp/arm/regexp-macro-assembler-arm.cc
index 6fafdfb4ad43cff4ba7068aa22006da4d414af21..f860c4ffd6e3f0d70f43e7a513d10950e087200e 100644
--- a/src/regexp/arm/regexp-macro-assembler-arm.cc
+++ b/src/regexp/arm/regexp-macro-assembler-arm.cc
@@ -798,9 +798,12 @@ Handle<HeapObject> RegExpMacroAssemblerARM::GetCode(Handle<String> source) {
         __ cmp(current_input_offset(), Operand::Zero());
         __ b(eq, &exit_label_);
         // Advance current position after a zero-length match.
+        Label advance;
+        __ bind(&advance);
         __ add(current_input_offset(),
                current_input_offset(),
                Operand((mode_ == UC16) ? 2 : 1));
+        if (global_unicode()) CheckNotInSurrogatePair(0, &advance);
       }
 
       __ b(&load_char_start_regexp);