[patch] fix --enable-gather-detailed-mem-stats

[Aldy Hernandez]

I guess no one has used --enable-gather-detailed-mem-stats in a while, 
because it doesn't even build.

Fixed with the attached patch.
Tested by building cc1plus/cc1 with --enable-gather-detailed-mem-stats.

Committed to mainline.
commit 458f0b8665bc5adc99b5095d812089e918d62176
Author: Aldy Hernandez <al...@redhat.com>
Date:   Tue Feb 24 13:49:56 2015 -0800

        * gimple.h (gimple_build_assign): Rename CXX_MEM_STAT_DECL to
        CXX_MEM_STAT_INFO.

diff --git a/gcc/gimple.h b/gcc/gimple.h
index 5503625..95e4fc8 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -1303,7 +1303,7 @@ gcall *gimple_build_call_valist (tree, unsigned, va_list);
 gcall *gimple_build_call_internal (enum internal_fn, unsigned, ...);
 gcall *gimple_build_call_internal_vec (enum internal_fn, vec<tree> );
 gcall *gimple_build_call_from_tree (tree);
-gassign *gimple_build_assign (tree, tree CXX_MEM_STAT_DECL);
+gassign *gimple_build_assign (tree, tree CXX_MEM_STAT_INFO);
 gassign *gimple_build_assign (tree, enum tree_code,
                              tree, tree, tree CXX_MEM_STAT_INFO);
 gassign *gimple_build_assign (tree, enum tree_code,