This now tests the interface between parse-partial-sexp and the low level
comment function in syntax.c
* test/src/syntax-tests.el (syntax-comments-midpoint): New function.
(syntax-pps-comments): New macro.
(top level): Two new syntax-br-comments tests and five new syntax-pps-comments
tests.
* test/data/syntax-comments.txt (top level): Amend some test fragments and add
some more.