Ada: unable to compare strings (Attempt to compare array with non-array)

Ada: unable to compare strings (Attempt to compare array with non-array)

Consider the following Ada Code:

   type Str is new String (1 .. 4);
   My_str : Str := "ABCD";

This simply declares a 4-character string type. Trying to perform
equality tests using it currently yield an error:

    (gdb) p my_str = my_str
    Attempt to compare array with non-array
    (gdb) p my_str = "ABCD"
    Attempt to compare array with non-array

The error occurs because my_str is defined as an object whose
type is a typdef to a TYPE_CODE_ARRAY, which ada_value_equal
is not expecting at all (yet). This patch fixes this oversight.

gdb/ChangeLog:

        * ada-lang.c (ada_value_equal): Add handling of typedef types
        when comparing array objects.

gdb/testsuite/ChangeLog:

        * gdb.ada/str_binop_equal: New testcase.

Tested on x86_64-linux.