Fixed issue v8:1644 (bug in the chaining of fixup position)

test/cctest/test-assembler-x64.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 28 matching lines @@
 using v8::internal::CodeDesc;
 using v8::internal::FUNCTION_CAST;
 using v8::internal::Immediate;
 using v8::internal::Isolate;
 using v8::internal::Label;
 using v8::internal::OS;
 using v8::internal::Operand;
 using v8::internal::byte;
 using v8::internal::greater;
 using v8::internal::less_equal;
+using v8::internal::equal;
 using v8::internal::not_equal;
 using v8::internal::r13;
 using v8::internal::r15;
 using v8::internal::r8;
 using v8::internal::r9;
 using v8::internal::rax;
 using v8::internal::rbp;
 using v8::internal::rcx;
 using v8::internal::rdi;
 using v8::internal::rdx;
@@ skipping 279 matching lines @@
     CHECK(!Operand(rbp, rax, times_1, offset).AddressUsesRegister(rsp));
 
     CHECK(Operand(rsp, rbp, times_1, offset).AddressUsesRegister(rsp));
     CHECK(Operand(rsp, rbp, times_1, offset).AddressUsesRegister(rbp));
     CHECK(!Operand(rsp, rbp, times_1, offset).AddressUsesRegister(rax));
     CHECK(!Operand(rsp, rbp, times_1, offset).AddressUsesRegister(r15));
     CHECK(!Operand(rsp, rbp, times_1, offset).AddressUsesRegister(r13));
   }
 }
 
+
+TEST(AssemblerX64LabelChaining) {
+  // Test chaining of label usages within instructions (issue 1644).
+  v8::HandleScope scope;
+  Assembler assm(Isolate::Current(), NULL, 0);
+
+  Label target;
+  __ j(equal, &target);
+  __ j(not_equal, &target);
+  __ bind(&target);
+  __ nop();
+}
+
 #undef __