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diff --git a/src/3rdparty/masm/wtf/PageReservation.h b/src/3rdparty/masm/wtf/PageReservation.h
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+/*
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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 with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef PageReservation_h
+#define PageReservation_h
+
+#include <wtf/PageAllocation.h>
+
+namespace WTF {
+
+/*
+    PageReservation
+
+    Like PageAllocation, the PageReservation class provides a cross-platform memory
+    allocation interface, but with a set of capabilities more similar to that of
+    VirtualAlloc than posix mmap.  PageReservation can be used to allocate virtual
+    memory without committing physical memory pages using PageReservation::reserve.
+    Following a call to reserve all memory in the region is in a decommited state,
+    in which the memory should not be used (accessing the memory may cause a fault).
+
+    Before using memory it must be committed by calling commit, which is passed start
+    and size values (both of which require system page size granularity).  One the
+    committed memory is no longer needed 'decommit' may be called to return the
+    memory to its devommitted state.  Commit should only be called on memory that is
+    currently decommitted, and decommit should only be called on memory regions that
+    are currently committed.  All memory should be decommited before the reservation
+    is deallocated.  Values in memory may not be retained accross a pair of calls if
+    the region of memory is decommitted and then committed again.
+
+    Memory protection should not be changed on decommitted memory, and if protection
+    is changed on memory while it is committed it should be returned to the orignal
+    protection before decommit is called.
+*/
+
+class PageReservation : private PageBlock {
+public:
+    PageReservation()
+        : m_committed(0)
+        , m_writable(false)
+        , m_executable(false)
+    {
+    }
+
+    using PageBlock::base;
+    using PageBlock::size;
+
+#ifndef __clang__
+    using PageBlock::operator bool;
+#else
+    // FIXME: This is a workaround for <rdar://problem/8876150>, wherein Clang incorrectly emits an access
+    // control warning when a client tries to use operator bool exposed above via "using PageBlock::operator bool".
+    operator bool() const { return PageBlock::operator bool(); }
+#endif
+
+    void commit(void* start, size_t size)
+    {
+        ASSERT(*this);
+        ASSERT(isPageAligned(start));
+        ASSERT(isPageAligned(size));
+        ASSERT(contains(start, size));
+
+        m_committed += size;
+        OSAllocator::commit(start, size, m_writable, m_executable);
+    }
+
+    void decommit(void* start, size_t size)
+    {
+        ASSERT(*this);
+        ASSERT(isPageAligned(start));
+        ASSERT(isPageAligned(size));
+        ASSERT(contains(start, size));
+
+        m_committed -= size;
+        OSAllocator::decommit(start, size);
+    }
+
+    size_t committed()
+    {
+        return m_committed;
+    }
+
+    static PageReservation reserve(size_t size, OSAllocator::Usage usage = OSAllocator::UnknownUsage, bool writable = true, bool executable = false)
+    {
+        ASSERT(isPageAligned(size));
+        return PageReservation(OSAllocator::reserveUncommitted(size, usage, writable, executable), size, writable, executable, false);
+    }
+    
+    static PageReservation reserveWithGuardPages(size_t size, OSAllocator::Usage usage = OSAllocator::UnknownUsage, bool writable = true, bool executable = false)
+    {
+        ASSERT(isPageAligned(size));
+        return PageReservation(OSAllocator::reserveUncommitted(size + pageSize() * 2, usage, writable, executable, true), size, writable, executable, true);
+    }
+
+    void deallocate()
+    {
+        ASSERT(!m_committed);
+
+        // Clear base & size before calling release; if this is *inside* allocation
+        // then we won't be able to clear then after deallocating the memory.
+        PageReservation tmp;
+        std::swap(tmp, *this);
+
+        ASSERT(tmp);
+        ASSERT(!*this);
+
+        OSAllocator::releaseDecommitted(tmp.base(), tmp.size());
+    }
+
+private:
+    PageReservation(void* base, size_t size, bool writable, bool executable, bool hasGuardPages)
+        : PageBlock(base, size, hasGuardPages)
+        , m_committed(0)
+        , m_writable(writable)
+        , m_executable(executable)
+    {
+    }
+
+    size_t m_committed;
+    bool m_writable;
+    bool m_executable;
+};
+
+}
+
+using WTF::PageReservation;
+
+#endif // PageReservation_h