print_pc: fix multiple personalities support

* syscall.c (print_pc): Choose instruction pointer format depending
on current_wordsize, not the size of long integer type.
* tests/pc.c: New file.
* tests/pc.test: New test.
* tests/Makefile.am (check_PROGRAMS): Add pc.
(TESTS): Add pc.test.
* tests/.gitignore: Add pc.
5 files changed