[binutils-gdb] Remove char_ptr typedef

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT ec1f2d91e07522a77cbef7a438e132ff4a2a7839 ***

Author: Simon Marchi <simon.marchi@polymtl.ca>
Branch: master
Commit: ec1f2d91e07522a77cbef7a438e132ff4a2a7839

Remove char_ptr typedef

Now that all instances of VEC(char_ptr) are gone, we can remove the
typedef.  There is just one usage left, that is trivial to replace.

Tested by rebuilding on an enable-targets=all build.

gdb/ChangeLog:

	* common/gdb_vecs.h (char_ptr): Remove.
	* tracepoint.c (encode_actions_1): Remove usage of char_ptr.