gdb: remove some unnecessary watchpoint_addr_within_range overrides

While looking at the watchpoint code, I realised that AArch64, ARM,
and Loongarch all override watchpoint_addr_within_range with an
implementation that is the same as the default (but with the logic
written slightly differently).

Compare the deleted functions to default_watchpoint_addr_within_range
in target.c.

The only other targets that override watchpoint_addr_within_range are
ppc_linux_nat_target and remote_target, in both cases the
implementation is different to the default.

Lets remove these unnecessary overrides, and just use the default.

There should be no user visible changes after this commit.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

gdb/aarch64-nat.h

@@ -92,10 +92,6 @@ struct aarch64_nat_target : public BaseTarget
   int remove_hw_breakpoint (struct gdbarch *gdbarch,
 			    struct bp_target_info *bp_tgt) override
   { return aarch64_remove_hw_breakpoint (gdbarch, bp_tgt); }
-
-  bool watchpoint_addr_within_range (CORE_ADDR addr, CORE_ADDR start,
-				     int length) override
-  { return start <= addr && start + length - 1 >= addr; }
 };
 
 #endif /* GDB_AARCH64_NAT_H */

gdb/arm-linux-nat.c

@@ -90,8 +90,6 @@ public:
 
   bool stopped_data_address (CORE_ADDR *) override;
 
-  bool watchpoint_addr_within_range (CORE_ADDR, CORE_ADDR, int) override;
-
   const struct target_desc *read_description () override;
 
   /* Override linux_nat_target low methods.  */
@@ -1206,14 +1204,6 @@ arm_linux_nat_target::stopped_by_watchpoint ()
   return stopped_data_address (&addr);
 }
 
-bool
-arm_linux_nat_target::watchpoint_addr_within_range (CORE_ADDR addr,
-						    CORE_ADDR start,
-						    int length)
-{
-  return start <= addr && start + length - 1 >= addr;
-}
-
 /* Handle thread creation.  We need to copy the breakpoints and watchpoints
    in the parent thread to the child thread.  */
 void

gdb/loongarch-linux-nat.c

@@ -72,8 +72,6 @@ public:
 			 struct expression *cond) override;
   int remove_watchpoint (CORE_ADDR addr, int len, enum target_hw_bp_type type,
 			 struct expression *cond) override;
-  bool watchpoint_addr_within_range (CORE_ADDR addr, CORE_ADDR start,
-				     int length) override;
 
   /* Add our hardware breakpoint and watchpoint implementation.  */
   bool stopped_by_watchpoint () override;
@@ -581,15 +579,6 @@ loongarch_linux_nat_target::remove_watchpoint (CORE_ADDR addr, int len,
 
 }
 
-bool
-loongarch_linux_nat_target::watchpoint_addr_within_range (CORE_ADDR addr,
-							  CORE_ADDR start,
-							  int length)
-{
-  return start <= addr && start + length - 1 >= addr;
-}
-
-
 /* Implement the "stopped_data_address" target_ops method.  */
 
 bool