Fix syntax.h bug introduced by recent INLINE change.

Fix syntax.h bug introduced by recent INLINE change.

syntax.h defined an extern inline function SYNTAX_ENTRY that was
conditionally compiled one way in some modules, and a different
way in others.  This doesn't work with extern inline functions,
which must have the same definition in all modules, because the
defining code might be shared across modules, depending on the
implementation.  Symptoms reported by Martin Rudalics in:
http://lists.gnu.org/archive/html/emacs-devel/2013-09/msg00414.html
* regex.c, syntax.c (SYNTAX_ENTRY_VIA_PROPERTY): Remove.
(SYNTAX, SYNTAX_ENTRY, SYNTAX_WITH_FLAGS): New macros,
overriding the corresponding functions in syntax.h.
* syntax.h (syntax_property_entry, syntax_property_with_flags)
(syntax_property): New inline functions.
(SYNTAX_ENTRY, SYNTAX_WITH_FLAGS, SYNTAX):
Rewrite in terms of these new functions.