(struct directive, directive_table, handle_directive): pass_thru now 1 for #define...

(struct directive, directive_table, handle_directive): pass_thru now 1 for #define and 2 for #pragma.

(struct directive, directive_table, handle_directive): pass_thru now 1 for
#define and 2 for #pragma.
(handle_directive): When deciding whether to suppress comment at end of
directive, ignore tabs and spaces after comment.  Remove redundant limit test.
With -dD -C, copy comment when isolating definition.
(skip_to_end_of_comment): With -C, don't copy newline at end of C++ comment.

From-SVN: r12831