gdb/

	gdb/
	* infrun.c (proceed): Revert previous change.
	(resume): Instead, handle the case of signal delivery while stepping
	off a breakpoint location here, and only if software single-stepping
	is used.  Handle nested signals.

	gdb/testsuite/
	* gdb.base/signest.exp: New file.
	* gdb.base/signest.c: Likewise.