schema BUGFIX separate special values in statements enumeration

There are special values representing syntax tokens (semicolon, braces,
...) in the enumeration list of statements. They extend the list to be
usable by the schema parsers to cover all the syntax tokens. But they
are supposed to be separated at the end of the list (parsers lean on
it).
diff --git a/src/tree_schema.h b/src/tree_schema.h
index 7a8233a..cf825d1 100644
--- a/src/tree_schema.h
+++ b/src/tree_schema.h
@@ -328,8 +328,6 @@
 
 /* rest */
     LY_STMT_ARGUMENT,
-    LY_STMT_ARG_TEXT,
-    LY_STMT_ARG_VALUE,
     LY_STMT_BASE,
     LY_STMT_BELONGS_TO,
     LY_STMT_BIT,
@@ -380,9 +378,6 @@
     LY_STMT_REVISION_DATE,
     LY_STMT_STATUS,             /**< in ::lysc_ext_substmt.storage stored as a pointer to `uint16_t`, only cardinality < #LY_STMT_CARD_SOME is allowed */
     LY_STMT_SUBMODULE,
-    LY_STMT_SYNTAX_SEMICOLON,
-    LY_STMT_SYNTAX_LEFT_BRACE,
-    LY_STMT_SYNTAX_RIGHT_BRACE,
     LY_STMT_TYPE,               /**< in ::lysc_ext_substmt.storage stored as a pointer to `struct lysc_type *` (cardinality < #LY_STMT_CARD_SOME)
                                      or as a pointer to a [sized array](@ref sizedarrays) `struct lysc_type **` */
     LY_STMT_TYPEDEF,
@@ -392,7 +387,21 @@
     LY_STMT_VALUE,
     LY_STMT_WHEN,
     LY_STMT_YANG_VERSION,
-    LY_STMT_YIN_ELEMENT
+    LY_STMT_YIN_ELEMENT,
+
+    /* separated from the list of statements
+     * the following tokens are part of the syntax and parsers have to work
+     * with them, but they are not a standard YANG statements
+     */
+    LY_STMT_SYNTAX_SEMICOLON,
+    LY_STMT_SYNTAX_LEFT_BRACE,
+    LY_STMT_SYNTAX_RIGHT_BRACE,
+
+    /*
+     * YIN-specific tokens, still they are part of the syntax, but not the standard statements
+     */
+    LY_STMT_ARG_TEXT,
+    LY_STMT_ARG_VALUE
 };
 
 /**