Fix PR gdb/66.

Fix PR gdb/66.
* gdb.base/structs.exp: Replace skip for a29k with skip for
gdb,cannot_call_functions.
* gdb.base/call-ar-st.exp: Remove references to a29k in comments.
* gdb.base/callfuncs.exp: Ditto.
* gdb.base/call-rt-st.exp: Ditto.
* gdb.base/call-strs.exp: Ditto.
* gdb.base/callfwmall.exp: Ditto.
* gdb.base/scope.exp: Obsolete xfail a29k.
* gdb.c++/misc.exp: Ditto.
* gdb.c++/cplusfuncs.exp: Ditto.
* gdb.base/ptype.exp: Ditto.
* gdb.base/printcmds.exp: Ditto.
* gdb.base/opaque.exp: Ditto.
* gdb.base/list.exp: Ditto.
* gdb.base/funcargs.exp: Ditto.
* gdb.base/default.exp: Ditto.