Dynamic values have been around (and stable and reliable) for long enough that...

Dynamic values have been around (and stable and reliable) for long enough that we can turn them on by default

Change the default of prefer-dynamic-value to eDynamicDontRunTarget (i.e. enable dynamic values, but do not run code to do so)

Of course, disable this for the test suite, since testing no-dynamic-values is actually valuable

Fixes rdar://17363061

llvm-svn: 225486