Merge GDB 7.5.1

gdb/gnulib/import/extra/snippet/warn-on-use.h

 /* A C macro for emitting warnings if a function is used.
-   Copyright (C) 2010, 2011 Free Software Foundation, Inc.
+   Copyright (C) 2010-2012 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published
    by the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
+   General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* _GL_WARN_ON_USE (function, "literal string") issues a declaration
    for FUNCTION which will then trigger a compiler warning containing
    the text of "literal string" anywhere that function is called, if
    supported by the compiler.  If the compiler does not support this
    feature, the macro expands to an unused extern declaration.
 
@@ skipping 77 matching lines @@
 
 /* _GL_WARN_EXTERN_C declaration;
    performs the declaration with C linkage.  */
 #ifndef _GL_WARN_EXTERN_C
 # if defined __cplusplus
 #  define _GL_WARN_EXTERN_C extern "C"
 # else
 #  define _GL_WARN_EXTERN_C extern
 # endif
 #endif