Include what you use for the preparser.

src/globals.h

Index: src/globals.h
diff --git a/src/globals.h b/src/globals.h
index 30b676c8bd155d71503f7039ae5ba52b56f78447..5d39a20a7ea2f02e089499d7072197f4f318b5e9 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -1,4 +1,4 @@
-// Copyright 2011 the V8 project authors. All rights reserved.
+// Copyright 2012 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:
@@ -28,6 +28,8 @@
 #ifndef V8_GLOBALS_H_
 #define V8_GLOBALS_H_
 
+#include <math.h>
+
 // Define V8_INFINITY
 #define V8_INFINITY INFINITY
 
@@ -57,7 +59,7 @@
 #endif
 
 
-#include "../include/v8stdint.h"
+#include "../include/v8stdint.h"  // IWYU pragma: export
 
 namespace v8 {
 namespace internal {