gdb: fix documentation of gdbarch_displaced_step_copy_insn

I spotted something that looks wrong in the doc of
gdbarch_displaced_step_copy_insn.

It says that if the function returns NULL, it means that it has emulated
the behavior of the instruction and written the result to REGS.
However, it says below that the function may return NULL to indicate
that the instruction can't be single-stepped out-of-line, in which case
the core steps the instruction in-line.  The two are contradictory.

The right one is the latter, if the function returns NULL, the core
falls back to in-line stepping. I checked all the implementations of
this function and they all agree with this.

gdb/ChangeLog:

	* gdbarch.sh (displaced_step_copy_insn): Update doc.
	* gdbarch.h: Re-generate.

Change-Id: I98163cdd38970cde4c77680e249b10f5d2d5bf9b

1 files changed, 1 insertions, 3 deletions

diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index d7e7c498d9e..4e51c295b36 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -1007,9 +1007,7 @@ extern void set_gdbarch_max_insn_length (struct gdbarch *gdbarch, ULONGEST max_i
    not the copy at TO.  The caller should update it to point at TO later.
   
    Return a pointer to data of the architecture's choice to be passed
-   to gdbarch_displaced_step_fixup.  Or, return NULL to indicate that
-   the instruction's effects have been completely simulated, with the
-   resulting state written back to REGS.
+   to gdbarch_displaced_step_fixup.
   
    For a general explanation of displaced stepping and how GDB uses it,
    see the comments in infrun.c.