Remove preprocessor conditionals for ANSI-standard signals

Remove preprocessor conditionals for ANSI-standard signals

The six signals SIGINT, SIGILL, SIGABRT, SIGFPE, SIGSEGV and SIGTERM
are ANSI-standard and thus guaranteed to be available.  This patch
removes all preprocessor conditionals relating to these symbols.

gdb/
2014-06-06  Gary Benson  <gbenson@redhat.com>

	* common/signals.c: Remove preprocessor conditionals for
	always-defined signals SIGINT, SIGILL, SIGABRT, SIGFPE,
	SIGSEGV and SIGTERM.
	* proc-events.c: Likewise.

gdb/testsuite/
2014-06-06  Gary Benson  <gbenson@redhat.com>

	* gdb.base/call-signals.c: Remove preprocessor conditionals
	for always-defined signals SIGINT, SIGILL, SIGABRT, SIGFPE,
	SIGSEGV and SIGTERM.
	* gdb.base/sigall.c: Likewise.
	* gdb.base/unwindonsignal.c: Likewise.
	* gdb.reverse/sigall-reverse.c: Likewise.