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

src/regexp/x64/regexp-macro-assembler-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/regexp/x64/regexp-macro-assembler-x64.h"
 
 #include "src/log.h"
 #include "src/macro-assembler.h"
@@ skipping 859 matching lines @@
       if (global_with_zero_length_check()) {
         // Special case for zero-length matches.
         // rdx: capture start index
         __ cmpp(rdi, rdx);
         // Not a zero-length match, restart.
         __ j(not_equal, &load_char_start_regexp);
         // rdi (offset from the end) is zero if we already reached the end.
         __ testp(rdi, rdi);
         __ j(zero, &exit_label_, Label::kNear);
         // Advance current position after a zero-length match.
+        Label advance;
+        __ bind(&advance);
         if (mode_ == UC16) {
           __ addq(rdi, Immediate(2));
         } else {
           __ incq(rdi);
         }
+        if (global_unicode()) CheckNotInSurrogatePair(0, &advance);
       }
 
       __ jmp(&load_char_start_regexp);
     } else {
       __ movp(rax, Immediate(SUCCESS));
     }
   }
 
   __ bind(&exit_label_);
   if (global()) {
@@ skipping 496 matching lines @@
 }
 
 #undef __
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64