Rename max_sharing files

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/kernel/CMakeLists.txt

@@ -1,2 +1,2 @@
-add_library(kernel expr.cpp expr_max_shared)
+add_library(kernel expr.cpp max_sharing)
 target_link_libraries(kernel ${EXTRA_LIBS})

src/kernel/max_sharing.cpp

@@ -6,7 +6,7 @@ Author: Leonardo de Moura
 */
 #include <unordered_set>
 #include <vector>
-#include "expr_max_shared.h"
+#include "expr.h"
 #include "expr_functors.h"
 
 namespace lean {

src/tests/kernel/expr.cpp

@@ -5,8 +5,8 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Author: Leonardo de Moura
 */
 #include "expr.h"
-#include "expr_max_shared.h"
 #include "expr_set.h"
+#include "max_sharing.h"
 #include "test.h"
 #include <algorithm>
 using namespace lean;