X64: Implement RegExp natively.

src/regexp-stack.h

Index: src/regexp-stack.h
diff --git a/src/regexp-stack.h b/src/regexp-stack.h
index 6c090daa6526a8d0a4b6ee3b1d86aca24c01ae5b..eb6df6a92d0fd0a2fc50de4a39fff964abd6b576 100644
--- a/src/regexp-stack.h
+++ b/src/regexp-stack.h
@@ -48,7 +48,7 @@ class RegExpStack {
   ~RegExpStack();  // Releases the stack if it has grown.
 
   // Gives the top of the memory used as stack.
-  static Address stack_top() {
+  static Address stack_base() {
     ASSERT(thread_local_.memory_size_ != 0);
     return thread_local_.memory_ + thread_local_.memory_size_;
   }
@@ -74,7 +74,7 @@ class RegExpStack {
 
  private:
   // Artificial limit used when no memory has been allocated.
-  static const uint32_t kMemoryTop = 0xffffffff;
+  static const uintptr_t kMemoryTop = -1;
 
   // Minimal size of allocated stack area.
   static const size_t kMinimumStackSize = 1 * KB;