Fix issue 493: Infinite loop when debug break is set when entering function.apply

src/x64/regexp-macro-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 625 matching lines @@
   __ push(r9);
 
   __ push(rbx);  // Callee-save
 #endif
   __ push(Immediate(0));  // Make room for "input start - 1" constant.
 
   // Check if we have space on the stack for registers.
   Label stack_limit_hit;
   Label stack_ok;
 
-  ExternalReference stack_guard_limit =
-      ExternalReference::address_of_stack_guard_limit();
+  ExternalReference stack_limit =
+      ExternalReference::address_of_stack_limit();
   __ movq(rcx, rsp);
-  __ movq(kScratchRegister, stack_guard_limit);
+  __ movq(kScratchRegister, stack_limit);
   __ subq(rcx, Operand(kScratchRegister, 0));
   // Handle it if the stack pointer is already below the stack limit.
   __ j(below_equal, &stack_limit_hit);
   // Check if there is room for the variable number of registers above
   // the stack limit.
   __ cmpq(rcx, Immediate(num_registers_ * kPointerSize));
   __ j(above_equal, &stack_ok);
   // Exit with OutOfMemory exception. There is not enough space on the stack
   // for our working registers.
   __ movq(rax, Immediate(EXCEPTION));
@@ skipping 529 matching lines @@
 
 
 void RegExpMacroAssemblerX64::Drop() {
   __ addq(backtrack_stackpointer(), Immediate(kIntSize));
 }
 
 
 void RegExpMacroAssemblerX64::CheckPreemption() {
   // Check for preemption.
   Label no_preempt;
-  ExternalReference stack_guard_limit =
-      ExternalReference::address_of_stack_guard_limit();
-  __ load_rax(stack_guard_limit);
+  ExternalReference stack_limit =
+      ExternalReference::address_of_stack_limit();
+  __ load_rax(stack_limit);
   __ cmpq(rsp, rax);
   __ j(above, &no_preempt);
 
   SafeCall(&check_preempt_label_);
 
   __ bind(&no_preempt);
 }
 
 
 void RegExpMacroAssemblerX64::CheckStackLimit() {
@@ skipping 71 matching lines @@
                  Operand(rsi, rdi, times_1, cp_offset * sizeof(uc16)));
     }
   }
 }
 
 #undef __
 
 #endif  // V8_NATIVE_REGEXP
 
 }}  // namespace v8::internal