[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 f5d25087460a6dadf4cbc64067ff2465609f9dd0..ce72188ae1f3b81ca05c412ee8a48abb50caf5f7 100644
--- a/src/regexp/arm/regexp-macro-assembler-arm.cc
+++ b/src/regexp/arm/regexp-macro-assembler-arm.cc
@@ -805,9 +805,12 @@ 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);