[analyzer] Incorrect configurations of regression test cases related to Z3

found in #180801

* In clang/test/Analysis/z3-unarysymexpr.c, the requirement condition is wrong: "Z3" -> "z3" (also with a missed correct output for -Wunused-value)
* z3-related test cases are not in the z3 subdirectory
- clang/test/Analysis/z3-crosscheck.c
- clang/test/Analysis/unary-sym-expr-z3-refutation.c
- clang/test/Analysis/cstring-addrspace.c **Should this also be put into the z3 subdirectory?**
- clang/test/Analysis/bitint-z3.c
- clang/test/Analysis/z3-crosscheck-max-attempts.cpp
- clang/test/Analysis/PR37855.c
- clang/test/Analysis/z3-refute-enum-crash.cpp

Should I fix the above with one or two PRs?