Adding the to be loaded dylib to the extra images causes the breakpoint
to be found in the image added to the target on Linux (though not on
Darwin). So adjust the test for this difference.
I added some tests for the case where the breakpoints take immediately
to the extant test case, and made a new test case for when the source
regex breakpoint will be set in a dlopen-ed library.
I also noticed when doing this that "lldbutil.run_to_source_breakpoint
can't handle the case where the breakpoint will be in a dlopen-ed
library, since it requires the breakpoint to have at least 1 location
before run. I fixed that by adding a parameter to say whether a
before run location is expected.
Differential Revision: https://reviews.llvm.org/D111920