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

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

Index: src/x64/regexp-macro-assembler-x64.cc
===================================================================
--- src/x64/regexp-macro-assembler-x64.cc	(revision 3200)
+++ src/x64/regexp-macro-assembler-x64.cc	(working copy)
@@ -643,10 +643,10 @@
   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);
@@ -1196,9 +1196,9 @@
 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);