sourceware.org/ml/gdb-patches/2013-07/msg00059.html
gdb/ChangeLog
* stack.c (read_frame_arg): No longer fetch lazy values.
* value.c (value_optimized_out): If the value is not already
marked optimized out, and is lazy then fetch it.
(value_primitive_field): Move optimized out check to later in the
function, after we have loaded any lazy values.
(value_fetch_lazy): Use optimized out flag directly rather than
calling optimized_out method.
gdb/testsuite/ChangeLog
* gdb.dwarf2/dw2-reg-undefined.exp: New file.
* gdb.dwarf2/dw2-reg-undefined.c: Likewise.
* gdb.dwarf2/dw2-reg-undefined.S: Likewise.