cfg-grammar: fix the precedence of ';'

In 6d74e60, the precedence of ';' has
implicitly changed for filter rules, changing the meaning of filter
expressions:

The expression `not program("a"); message("b");` should have the following
interpretation: `(not program("a")) and message("b")`.

Due to accidentally changed precedence of ';', currently it is interpreted
as `not (message("a") and message("b"))`.

This patch recovers the original precedence, but also introduces
precedence and left associativity for other semicolon-separated rules.

All the other (non-filter) uses of the ';' token are unambiguous, so this
declaration won't interfere with those rules.

Signed-off-by: László Várady <laszlo.varady@anno.io>
Signed-off-by: Attila Szakacs <attila.szakacs@axoflow.com>

lib/cfg-grammar.y

@@ -157,6 +157,9 @@
 /* this is a placeholder for unit tests, must be the latest & largest */
 %token LL_CONTEXT_MAX                 27
 
+
+%left   ';'
+
 /* operators in the filter language, the order of this determines precedence */
 %right KW_ASSIGN 9000
 %right '?' ':'

lib/filter/filter-expr-grammar.ym

@@ -112,8 +112,6 @@ _translate_number_literals(CfgLexer *lexer, gint compare_mode, LogTemplate *expr
 %token KW_PROGRAM
 %token KW_IN_LIST
 
-%left   ';'
-
 %type	<node> filter_expr
 %type	<node> filter_simple_expr
 %type	<node> filter_plugin