Remove references to removed Valgrind headers

COPYRIGHT

@@ -22,104 +22,6 @@ The Rust Project includes packages written by third parties.
 The following third party packages are included, and carry
 their own copyright notices and license terms:
 
-* Two header files that are part of the Valgrind
-  package. These files are found at src/rt/valgrind/valgrind.h and
-  src/rt/valgrind/memcheck.h, within this distribution. These files
-  are redistributed under the following terms, as noted in
-  them:
-
-  for src/rt/valgrind/valgrind.h:
-
-    This file is part of Valgrind, a dynamic binary
-    instrumentation framework.
-
-    Copyright (C) 2000-2010 Julian Seward.  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. The origin of this software must not be
-       misrepresented; you must not claim that you wrote the
-       original software.  If you use this software in a
-       product, an acknowledgment in the product
-       documentation would be appreciated but is not
-       required.
-
-    3. Altered source versions must be plainly marked as
-       such, and must not be misrepresented as being the
-       original software.
-
-    4. The name of the author may not be used to endorse or
-       promote products derived from this software without
-       specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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.
-
-  for src/rt/valgrind/memcheck.h:
-
-    This file is part of MemCheck, a heavyweight Valgrind
-    tool for detecting memory errors.
-
-    Copyright (C) 2000-2010 Julian Seward.  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. The origin of this software must not be
-       misrepresented; you must not claim that you wrote the
-       original software.  If you use this software in a
-       product, an acknowledgment in the product
-       documentation would be appreciated but is not
-       required.
-
-    3. Altered source versions must be plainly marked as
-       such, and must not be misrepresented as being the
-       original software.
-
-    4. The name of the author may not be used to endorse or
-       promote products derived from this software without
-       specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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.
-
 * The src/rt/miniz.c file, carrying an implementation of
   RFC1950/RFC1951 DEFLATE, by Rich Geldreich
   <richgel99@gmail.com>. All uses of this file are