Simple testsuite for DTrace USDT probes.

Simple testsuite for DTrace USDT probes.

This patch adds some simple tests testing the support for DTrace USDT
probes.  The testsuite will be skipped as unsupported in case the user
does not have DTrace installed on her system.  The tests included in the
test suite test breakpointing on DTrace probes, enabling and disabling
probes, printing of probe arguments of several types and also
breakpointing on several probes with the same name.

gdb/ChangeLog:

2015-02-17  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* lib/dtrace.exp: New file.
	* gdb.base/dtrace-probe.exp: Likewise.
	* gdb.base/dtrace-probe.d: Likewise.
	* gdb.base/dtrace-probe.c: Likewise.
	* lib/pdtrace.in: Likewise.
	* configure.ac: Output variables with the transformed names of
	the strip, readelf, as and nm tools.  AC_SUBST lib/pdtrace.in.
	* configure: Regenerated.