Replace %defaultOpts with explicit pass names

This replaces the use of %defaultOpts = '-basicaa -polly-prepare' with the
minimal set of passes necessary for a test to succeed. Of the test cases that
previously used %defaultOpts 76 test cases require none of these passes, 42
need -basicaa and only 2 need -polly-prepare. Our change makes this requirement
explicit.

In Polly many test cases have been using a macro '%defaultOpts' which run a
couple of preparing passes before the actual Polly test case. This macro was
introduced very early in the development of Polly and originally contained a
large set of canonicalization passes.  However, as the need for additional
canonicalization passes makes test cases harder to understand and also more
fragile in terms of changes in such passes, we aim since a longer time to only
include the minimal set of passes necessary. This patch removes the last
leftovers from of %defaultOpts and brings our tests cases more in line to what
is usus in LLVM itself.