py-type.exp: Do not run tests if binary fails to build

py-type.exp: Do not run tests if binary fails to build

I noticed this while working on the test case.  I believe it would make
sense to skip running the tests if the binary failed to build.  Although
I would understand the opposite argument: if the binary does not build
for some reason, we probably want to know about it, and some catastrophic
failures in the tests might alarm us better than a timid "UNTESTED".

gdb/testsuite/ChangeLog:

	* gdb.python/py-type.exp: Do not run tests if binaries fail to
	build.