test: Blacklist 987-stack-trace-dumping for javac/dx

Very many tests are currently failing because they import libcore code
which isn't on the standard javac classpath. This new test is one of
those.

A future commit will properly fix this type of failure for all javac/dx
tests, until then simply blacklist it.

Bug: 37636792
Change-Id: Id727372c10ec3ea3ff5913ea8e74c209d3dee575