Move part of scanner.* into scanner-base.* for reuse in preparser scanner.

src/checks.h

Index: src/checks.h
diff --git a/src/checks.h b/src/checks.h
index 5ea59920ac1ee7497d7ee7c252e8906cb47600b6..e0704774ba453ecfee4daaff0de1987869b34a77 100644
--- a/src/checks.h
+++ b/src/checks.h
@@ -30,7 +30,7 @@
 
 #include <string.h>
 
-#include "flags.h"
+#include "../include/v8stdint.h"
 
 extern "C" void V8_Fatal(const char* file, int line, const char* format, ...);
 void API_Fatal(const char* location, const char* format, ...);
@@ -279,6 +279,12 @@ template <int> class StaticAssertionHelper { };
     SEMI_STATIC_JOIN(__StaticAssertTypedef__, __LINE__)
 
 
+namespace v8 { namespace internal {
+
+bool EnableSlowAsserts();
+
+} }  // namespace v8::internal
+
 // The ASSERT macro is equivalent to CHECK except that it only
 // generates code in debug builds.
 #ifdef DEBUG
@@ -287,7 +293,7 @@ template <int> class StaticAssertionHelper { };
 #define ASSERT_EQ(v1, v2)    CHECK_EQ(v1, v2)
 #define ASSERT_NE(v1, v2)    CHECK_NE(v1, v2)
 #define ASSERT_GE(v1, v2)    CHECK_GE(v1, v2)
-#define SLOW_ASSERT(condition) if (FLAG_enable_slow_asserts) CHECK(condition)
+#define SLOW_ASSERT(condition) if (EnableSlowAsserts()) CHECK(condition)
 #else
 #define ASSERT_RESULT(expr)     (expr)
 #define ASSERT(condition)      ((void) 0)
@@ -303,11 +309,16 @@ template <int> class StaticAssertionHelper { };
 // and release compilation modes behaviour.
 #define STATIC_ASSERT(test)  STATIC_CHECK(test)
 
+namespace v8 { namespace internal {
+
+intptr_t HeapObjectTagMask();
+
+} }  // namespace v8::internal
 
 #define ASSERT_TAG_ALIGNED(address) \
-  ASSERT((reinterpret_cast<intptr_t>(address) & kHeapObjectTagMask) == 0)
+  ASSERT((reinterpret_cast<intptr_t>(address) & HeapObjectTagMask()) == 0)
 
-#define ASSERT_SIZE_TAG_ALIGNED(size) ASSERT((size & kHeapObjectTagMask) == 0)
+#define ASSERT_SIZE_TAG_ALIGNED(size) ASSERT((size & HeapObjectTagMask()) == 0)
 
 #define ASSERT_NOT_NULL(p)  ASSERT_NE(NULL, p)