[tests] more ast-diff tests (with actual diff )

tests/syntax/ast_diff_1.i

 /* run.config
    MODULE: @PTEST_NAME@
-     OPT: -then -ast-diff %{dep:ast_diff_2.i}
+     OPT: -then -ast-diff %{dep:ast_diff_2.c}
+     OPT: -then -ast-diff %{dep:ast_diff_2.c} -cpp-extra-args="-DADD_ENUM_TAG"
 */
 int X;
 int Y=3;

tests/syntax/ast_diff_2.i → tests/syntax/ast_diff_2.c

@@ -90,7 +90,10 @@ void with_goto_unchanged(int c) {
 
 enum e {
   t = 1,
-  u = t + 2
+  u = t + 2,
+#ifdef ADD_ENUM_TAG
+  v = t + u,
+#endif
 };
 
 struct s { char c[t]; };

tests/syntax/oracle/ast_diff_1.res.oracle → tests/syntax/oracle/ast_diff_1.0.res.oracle

 [kernel] Parsing ast_diff_1.i (no preprocessing)
-[kernel] Parsing ast_diff_2.i (no preprocessing)
+[kernel] Parsing ast_diff_2.c (with preprocessing)
 [AST diff test] Showing correspondances between orig_default and default
 [AST diff test] Variable i:  => i
 [AST diff test] Variable local_var_use:  => local_var_use

tests/syntax/oracle/ast_diff_1.1.res.oracle

+[kernel] Parsing ast_diff_1.i (no preprocessing)
+[kernel] Parsing ast_diff_2.c (with preprocessing)
+[kernel] Parsing ast_diff_1.i (no preprocessing)
+[AST diff test] Showing correspondances between orig_default and default
+[AST diff test] Variable use_logic_builtin:  => use_logic_builtin
+[AST diff test] Variable x:  => x
+[AST diff test] Variable y:  => y
+[AST diff test] Variable has_static_local:  => has_static_local
+[AST diff test] Variable decl:  => decl
+[AST diff test] Variable used_in_decl:  => used_in_decl
+[AST diff test] Variable ptr_func:  => ptr_func
+[AST diff test] Variable i:  => i
+[AST diff test] Variable local_var_use:  => local_var_use
+[AST diff test] Variable v:  => w
+[AST diff test] Variable a:  => q
+[AST diff test] Variable x:  => z
+[AST diff test] Variable y:  => t
+[AST diff test] Variable s: N/A
+[AST diff test] Variable use_s: N/A
+[AST diff test] Variable with_goto_changed:  => with_goto_changed
+[AST diff test] Variable X:  => X
+[AST diff test] Variable Y: N/A
+[AST diff test] Variable c:  => c
+[AST diff test] Variable f:  => f
+[AST diff test] Variable with_goto_unchanged:  => with_goto_unchanged
+[AST diff test] Variable x:  => x
+[AST diff test] Variable c:  => c
+[AST diff test] Variable g:  => g
+[AST diff test] Variable se:  => se
+[AST diff test] Variable has_static_local_x:  => has_static_local_y
+[AST diff test] Variable h:  => h
+[AST diff test] Function use_logic_builtin:  => use_logic_builtin
+[AST diff test] Function has_static_local:  => has_static_local
+[AST diff test] Function decl:  => decl
+[AST diff test] Function i:  => i
+[AST diff test] Function local_var_use:  => local_var_use
+[AST diff test] Function use_s: N/A
+[AST diff test] Function with_goto_changed: -> with_goto_changed (body changed)
+[AST diff test] Function f:  => f
+[AST diff test] Function with_goto_unchanged:  => with_goto_unchanged
+[AST diff test] Function g: N/A
+[AST diff test] Function se: -> se (body changed)
+[AST diff test] Function h: -> h (body changed)