* amd64-tdep.c (amd64_skip_prefixes): Renamed from skip_prefixes.
All callers updated.
(amd64_get_insn_details): Handle more 3-byte opcode insns.
(amd64_breakpoint_p): Delete.
(amd64_displaced_step_fixup): When fixing up after stepping an int3,
don't back up pc to the start of the int3.
* i386-tdep.c: #include opcode/i386.h.
(i386_skip_prefixes): New function.
(i386_absolute_jmp_p): Constify argument.
(i386_absolute_call_p,i386_ret_p,i386_call_p,i386_syscall_p): Ditto.
(i386_breakpoint_p): Delete.
(i386_displaced_step_fixup): Handle unnecessary or redundant prefixes.
When fixing up after stepping an int3, don't back up pc to the start
of the int3.
* gdb.arch/amd64-disp-step.S (test_int3): New test.
* gdb.arch/amd64-disp-step.exp (test_int3): New test.
* gdb.arch/i386-disp-step.S (test_prefixed_abs_jump): New test.
(test_prefixed_syscall,test_int3): New tests.
* gdb.arch/i386-disp-step.exp (test_prefixed_abs_jump): New test.
(test_prefixed_syscall,test_int3): New tests.