gdb/

	gdb/
	* infrun.c (handle_inferior_event): Move the check for return
	trampolines ahead of the check for function trampolines.
	* mips-tdep.h (MIPS_S2_REGNUM, MIPS_GP_REGNUM): New macros.
	* mips-tdep.c (mips_str_mips16_call_stub): New variable.
	(mips_str_mips16_ret_stub): Likewise.
	(mips_str_call_fp_stub): Likewise.
	(mips_str_call_stub): Likewise.
	(mips_str_fn_stub): Likewise.
	(mips_str_pic): Likewise.
	(mips_in_frame_stub): New function.
	(mips_unwind_pc): Return the return address rather than the PC
	if the PC of an intermediate frame is inside a call thunk.
	(mips_is_stub_suffix): New function.
	(mips_is_stub_mode): Likewise.
	(mips_get_mips16_fn_stub_pc): Likewise.
	(mips_skip_mips16_trampoline_code): Update to handle all the
	currently generated stub types.  Don't recurse into __fn_stub
	thunks.  Remove heuristics to handle stubs beyond etext/_etext.
	Use cooked register accesses.
	(mips_in_return_stub): Reintroduce function.
	(mips_skip_trampoline_code): Traverse trampolines recursively.
	(mips_gdbarch_init): Handle MIPS16 return trampolines.

	gdb/testsuite/
	* gdb.arch/mips16-thunks-inmain.c: New file.
	* gdb.arch/mips16-thunks-main.c: New file.
	* gdb.arch/mips16-thunks-sin.c: New file.
	* gdb.arch/mips16-thunks-sinfrob.c: New file.
	* gdb.arch/mips16-thunks-sinfrob16.c: New file.
	* gdb.arch/mips16-thunks-sinmain.c: New file.
	* gdb.arch/mips16-thunks-sinmips16.c: New file.
	* gdb.arch/mips16-thunks.exp: New file.