* breakpoint.h (enum bptype): Add bp_hardware_watchpoint and
bp_watchpoint_scope breakpoints.
(struct breakpoint): Add val_chain and related_breakpoint fields
for use by watchpoints.
* breakpoint.c (within_scope): Delete. No longer used.
(TARGET_CAN_USE_HARDWARE_WATCHPOINT): Provide default definition.
(target_{remove,insert}_watchpoint): Likewise.
(can_use_hardware_watchpoint): New function.
(remove_breakpoint): New function to remove a single breakpoint
or hardware watchpoint.
(insert_breakpoints): Handle insertion of hardware watchpoints.
Store a copy of the value chain derived from the watchpoint
expression.
(remove_breakpoints): Simplify by using remove_breakpoint.
(delete_breakpoint): Likewise.
(watchpoint_check): Delete the watchpoint and watchpoint scope
breakpoints when the watchpoint goes out of scope. Save & restore
the current frame after checking watchpoints.
(breakpoint_init_inferior): Likewise (restarting the program
makes all local watchpoints go out of scope).
(bpstat_stop_status): Handle hardware watchpoints much like normal
watchpoints. Delete the watchpoint and watchpoint scope breakpoint
when the watchpoint goes out of scope. Remove and reinsert all
breakpoints before returning if we stopped when a hardware watchpoint
fired.
(watch_command): Use a hardware watchpoint when possible. If
watching a local expression, build a scope breakpoint too.
(map_breakpoint_numbers): Also call given function for any
related breakpoints.
(disable_breakpoint): Never disable a scope breakpoint.
(enable_breakpoint): Handle hardware breakpoints much like normal
breakpoints, but recompute the watchpoint_scope breakpoint's
frame and address (if we have an associated scope breakpoint).
(read_memory_nobpt): Handle hardware watchpoints like normal
watchpoints. When necessary handle watchpoint_scope breakpoints.
(print_it_normal, bpstat_what, breakpoint_1, mention): Likewise.
(clear_command, breakpoint_re_set_one, enable_command): Likewise.
(disable_command): Likewise.
* blockframe.c (find_frame_addr_in_frame_chain): New function.
Extern prototype added to frame.h
* infrun.c (wait_for_inferior): Set current_frame and select
a frame before checking if we stopped due to a hardare watchpoint
firing. Handle stepping over hardware watchpoints.
(normal_stop): Remove unnecessary call to select_frame.
* value.h (value_release_to_mark): Declare.
* values.c (value_release_to_mark): New function.
* procfs.c (procfs_wait): Add cases for hardware watchpoints.
(procfs_set_watchpoint, procfs_stopped_by_watchpoint): New functions.
* hppab-nat.c (hppa_set_watchpoint): New function.
* config/pa/nm-hppab.h (STOPPED_BY_WATCHPOINT): Define.
(HAVE_STEPPABLE_WATCHPOINT): Define.
(TARGET_CAN_USE_HARDWARE_WATCHPOINT): Define.
(target_{insert,delete}_watchpoint): Define.