skeletons: fix comments

skeletons: fix comments

The commit 38de4e570fdc7c8db9633c3b2054e565d8c1c6b9 underquoted the
content of the comments, which resulted in losing square brackets in
the comments.  Besides, some other invocations were underquoting the
effective arguments.

* data/c.m4 (b4_comment_): Properly quote the comment.
(b4_comment_, b4_comment): Move to...
* data/c-like.m4: here, so that...
* data/java.m4: can use it instead of its own copy.
* data/bison.m4 (b4_integral_parser_tables_map): Fix some comments.

* data/lalr1.cc, data/lalr1.java, data/yacc.c: Comment fixes.

* data/lalr1.cc: Reorder a bit to factor some CPP directives.