Rename la_get_symbol_name_match_p into la_get_symbol_name_cmp

Rename la_get_symbol_name_match_p into la_get_symbol_name_cmp

The la_get_symbol_name_match_p language hook was poorly named, as
it suggested that the function should return nonzero if the names
match, whereas it is the exact opposite.  This patch therefore
renames the hook and associated typedef, as well some of the code
that uses that hook.

gdb/ChangeLog:

        * language.h (symbol_name_cmp_ftype): Renames
        symbol_name_match_p_ftype.
        (struct language_defn)[la_get_symbol_name_cmp]: Renames
        la_get_symbol_name_match_p.
        * ada-lang.c (ada_get_symbol_name_cmp): Renames
        ada_get_symbol_name_match_p.  Update comment.
        (ada_language_defn)[la_get_symbol_name_cmp]: Update value.
        * linespec.c (struct symbol_matcher_data)[symbol_name_cmp]:
        Renames symbol_name_match_p.  Update field type.
        (iterate_name_matcher, iterate_over_all_matching_symtabs): Adjust.
        * c-lang.c, d-lang.c, f-lang.c, jv-lang.c, m2-lang.c, objc-lang.c,
        opencl-lang.c, p-lang.c: Replace "la_get_symbol_name_match_p" by
        "la_get_symbol_name_cmp" in comments.
        * language.c: Likewise.